Canine Spleen Tumors: Common Symptoms and Treatment
Sarcoma hemangioma is one of the most aggressive tumors, collecting their deadly toll among our pupils. Angiosarcoma it is also one of the most common malignant tumors, located in the spleen of dogs.Spleen tumors in a dog
A female German Shepherd Dog was brought to the veterinary clinic. Brought on because the girl was unable to walk on her own.
In fact, it was the sudden onset of mobility problems that was the main motive for the consultation and the reason why caregivers decided to visit the veterinary clinic.
According to highly nervous owners, the dog had not shown anything unusual before - the dog's energy level and movement seemed perfectly normal. After returning from work, the owners of the bitch found her very sad and depressed, unable to stand up, breathing shallowly and quickly, lying on her side and abnormally poorly reacting to the return of her family home.
A glance at the mucous membranes and a quick clinical examination guided the physician to the choice of additional tests that should be performed in the first place.
Blood was collected for laboratory tests and ultrasound examination of the abdominal cavity was performed immediately.
Why ultrasound? Why blood tests? After all, the dog is not walking!
Why don't you take an x-ray, then you can clearly see that it's a bone or joint problem?
Initially, the owners did not understand why the doctor chose such a "strange" diagnostic procedure. They tried to argue with him and convince him of their arguments during the course of the study.
At one point, the ultrasound operator showed them something that completely changed the attitudes of concerned carers. On the monitor screen they saw a large, round "something" that - according to the researcher - was a large tumor on the spleen.
Terrified caregivers overhear devastating news: this tumor is most likely a fatal form of cancer called angiosarcoma.
The dog suffers from massive bleeding from this spleen mass and requires immediate surgery to have any chance of survival.
Unfortunately, in the case of emergency surgery, the disease usually ends in death within 2-3 months, and even in the case of aggressive chemotherapy after surgery, survival only extends to about 4-6 months.
However, there is a slight chance that the bleeding is due to a completely benign tumor which, if removed during the procedure, will cure the tumor. And there is no way to know if a dog has a malignant tumor or a benign lesion on the spleen before surgery and histopathological examination is performed.
Finding a tumor in the spleen is not always synonymous with the diagnosis of hemangiosarcoma. This organ may also have other types of changes, including benign tumors.
You can find out about what these changes can be, how they are diagnosed and treated, what the prognosis is for a dog diagnosed with spleen cancer, and much more about spleen tumors in dogs in this study. If you are interested in this topic, I invite you to read.
However, this article should definitely be read by owners of medium and large breed dogs, especially German Shepherds and Golden Retrievers.
- Why dog a spleen?
- Spleen functions
- Types of changes in a dog's spleen
- Non-neoplastic diseases that may be associated with the presence of foci in the spleen
- Neoplastic diseases that can cause foci to form in the spleen
- Malignant neoplasms
- Non-cancerous diseases that most often cause uniform enlargement of the spleen
- Neoplastic diseases that can cause generalized enlargement of the spleen
- Symptoms of tumors on a dog's spleen
- Diagnosis of tumors on the dog's spleen
- Tests used to evaluate the dog's spleen
- Treatment of spleen tumors in a dog
- Splenectomy in a dog
- Complications of splenectomy
- Whether a splenectomy is necessary?
- What if a lumpy lesion is found and the spleen is not removed??
- Post-operative care
- Prognosis for dog spleen tumors
- Hemangiosarcoma (haemangiosarcoma, HSA, sarcoma hemangioma)
- Occurrence of HSA in a dog
- Causes of spleen angiosarcoma in dogs
- Symptoms of hemangiosarcoma in a dog
- Diagnosis of spleen HSA in a dog
- Is there any chance of early detection of a dog's angiosarcoma?
- Treatment of spleen angiosarcoma in a dog
- Is it possible to find a drug for hemangiosarcoma?
- Therapies to help treat cancer in your dog
- How to Feed Your Dog with HSA Cancer?
- What is included in the dog's anti-cancer diet?
- Spleen angiosarcoma in dogs - prognosis
- Indications for putting a dog to sleep with hemangiosarcoma
Why dog a spleen?
The spleen is a relatively large, elongated, dark red organ, rich in numerous blood vessels and covered with a strong bag of fibrous tissue.
It is located in the upper left area of the abdomen, in the immediate vicinity of the stomach.
A normal spleen is shaped like a tongue; it is much longer than it is wider and slightly tapered in the middle. Blood vessels go in and out of the spleen at a place called the splenic hilum.
The spleen is the largest organ in the lymphatic system (often described as a large lymph node). This organ is also closely related to the cardiovascular system; it contains a network of vessels that transport fluid between tissues and blood.
The flesh of the spleen is made of red pulp and the lymphatic lumps dispersed in it, i.e. the white pulp.
Red pulp (rubra pulp) are areas for the formation and capture of red blood cells and the capture of immunogenic proteins called antigens.
It is formed by venous sinuses lined with endothelial cells.
Macrophages, cells presenting antigens, fibroblasts are arranged in the form of ropes along the sinuses filled with erythrocytes. Red pulp accounts for 4/5 of the mass of the spleen.
White pulp (alba pulp) are areas of special immune response cells called lymphocytes and reticuloendothelial cells.
These areas are made up of lymph nodes, which are organized lymphatic tissue. Their framework is made of reticulated filaments.
The marginal zone is the area that separates the white and red pulp and helps filter the blood.
The spleen, although not essential to life, has important functions related to the circulatory and lymphatic systems.
The functions of the spleen include:
- destruction and preservation of red blood cells,
- immune function.
Since the organ is directly connected to the bloodstream, it reacts faster than lymph nodes to antigens in the bloodstream.
The spleen produces specific blood cells and is the main site - outside the bone marrow - where red blood cells are made.
In utero, the spleen plays an important role in hematopoiesis, participating in the formation of red and white blood cells. Later, it is the bone marrow that takes over the role of the main hematopoietic organ, and the spleen ceases to count in this respect.
However, in some situations, e.g. in the course of various diseases (myelodysplastic syndromes, anemia, etc.) the spleen may regain haematopoietic activity.
The spleen is a kind of blood storage (it stores 10-20% of the total blood volume), becoming in some situations a natural "blood bank ".
It contains many long, narrow, tortuous blood vessels in which red blood cells circulate in great numbers.
This means that many erythrocytes gradually pass through the spleen at any given time, effectively making it a place where blood is stored.
At the time of hemorrhage, the smooth muscle fibers in the organ's parenchyma contract and a fresh supply of blood is pushed onto the perimeter. This ensures a specific, natural, immediate blood transfusion.
Blood cell graveyard
The spleen has the ability to filter out old, damaged, or abnormal blood cells.
Old erythrocytes are more fragile than their younger counterparts. As they move through the numerous, writhing splenic vessels, many of the older red blood cells no longer come out of the spleen, but travel through tight bends to burst releasing iron.
In this way, the spleen helps to remove old red blood cells from the circulation, which is sort of a cleansing function.
This organ also has a storage function for iron, which - released from disintegrating erythrocytes - is captured and processed by the spleen.
The spleen traps and removes old cells, bacteria and foreign proteins from the circulation.
It plays an important role in the removal of pathogens circulating in the blood located inside erythrocytes, e.g. Babesia protozoa.
The lack of this organ makes the course of the disease much more severe, treatment more difficult, and the number of deaths due to babesiosis is higher than in dogs with an intact spleen.
The spleen also has haemodynamic functions: it is a large reservoir of blood that is an important pool of blood that is released into the periphery in crisis situations.
It is covered with a connective tissue bag, from which connective tissue trabeculae, which constitute its framework, i.e. a scaffold, penetrate into the organ. Both the bag and the trabecula contain numerous smooth muscle fibers. With a sharp drop in blood pressure, the muscle fibers contract and the blood stored in the spleen is released into the periphery.
Maintaining the proper activity of the immune system and defending the body against certain types of infectious agents.
The spleen is part of the lymphatic system, but is slightly different from the lymph nodes.
The white pulp of the spleen sees the material from the level of the circulatory system and not from the level of the lymph vessels (as is the case with lymph nodes).
The spleen produces lymphocytes and most monocytes, and plays an important role in the production of antibodies.
Lymphocytes circulate through the white pulp of the spleen, as well as through lymphatic vessels, carrying messages related to the war against invaders (bacteria, viruses), taking part in fighting infection.
Types of changes in a dog's spleenTypes of changes in a dog's spleen
Different types of lesions can develop in the spleen, ranging from benign processes such as nodular hyperplasia or extramedullary hematopoiesis to life-threatening conditions such as lymphosarcoma and hemangiosarcoma.
Unfortunately, it is not possible to make a correct diagnosis without a biopsy. Despite the importance of this organ, there are no specific tests to assess the function of the spleen.
Changes in the spleen can be divided into changes in its structure located in the spleen of the correct size and disorders causing enlargement of the spleen.
The main abnormality in the spleen is splenomegaly, or enlargement of the spleen.
Splenomegaly (diffuse, uniform) - that is, even enlargement of the entire organ, with the tension of its capsule and rounded edges.
It is most often observed at:
- blood stagnation,
- acute and chronic inflammation,
- diffuse amyloidosis,
- diffuse and severe hematopoiesis,
- in some cancers (most often lymphoma, leukemia and mastocytoma).
Due to the accompanying presence of hyperemia, it can be divided into:
- changes with active or passive hyperemia - the so-called. spleen "bloody " (congested splenomegaly, "bloody " spleen);
- changes in which the congestion is not severe, the so-called. spleen "fleshy " (non-congested splenomegaly, "meaty " spleen).
Lumpy spenomegaly - characterized by the presence of nodules or tumors.
Given their appearance, it is distinguished by:
- Bloody nodules - dark cherry, soft, jelly-like, "bleeding " on the cross-section.
The form of blood nodules is taken by:
- angiomas and angiosarcomas,
- some nodular growths (e.g. red pulp hypertrophy of the spleen) and hemorrhagic infarction foci;
- Hard nodules (firm) - cherry, gray, brown or lard-like, harder, with little or no blood on the cross section.
The most common forms of hard nodules are:
- neoplasms not originating from endothelial cells (e.g. spindle cell sarcomas, histiocytic sarcomas, neoplastic metastases),
- nodular growths of the spleen,
- inflammatory granulomas,
Non-neoplastic diseases that may be associated with the presence of foci in the spleen
They account for about half the cases of all lesions seen in the spleen.
Despite the benign nature of these lesions, splenectomy is the treatment of choice in most cases.
This is due to the fact that at the preoperative stage it is rarely possible to distinguish neoplastic from non-neoplastic lesions, and even benign lesions, such as hematoma or nodular hyperplasia, risk rupture and life-threatening abdominal bleeding.
Sometimes the management is based on the monitoring of splenic changes at regular intervals using ultrasound and laboratory tests.
In some cases, it is possible to perform a fine needle aspiration biopsy and collect material for cytological examination, which may be helpful in determining whether surgery is really necessary.
Hematomas are the most common noncancerous tumors of the spleen in dogs.
These are blood extravasations within the spleen tissue, during which blood from the vascular bed moves to the spleen parenchyma or between its capsule and parenchyma and accumulates there.
The hematoma usually appears as a tumor (or multiple tumors), most often spherical, symmetrical with a smooth surface; sometimes it may be less regular in shape.
The sizes of hematomas vary: from several millimeter nodules to huge tumors, measuring even several dozen centimeters. Macroscopically, the spleen hematoma is indistinguishable from a hemangiosarcoma (malignant tumor).
Hematomas in the spleen may be the result of an injury or may accompany non-neoplastic processes (especially nodular hyperplasia) or neoplastic (especially angiosarcoma) growths of the spleen. Sometimes the cause of their formation is not clear.
Often, dogs with spleen hematomas do not have any underlying causes. The problem is simply that the hematoma has grown too large and interferes with the normal functioning of the digestive tract, or it has ruptured, causing bleeding into the abdominal cavity.
German Shepherds and Poodles appear to be predisposed to haematomas. Dogs with spleen hematoma have a good prognosis if it is surgically removed (most commonly splenectomy).
Nodular hyperplasia is a mild overproduction of the spleen's lymphatic elements.
In nodular hyperplasia, one or more spleen cell lines proliferate profoundly (but not neoplastic) - this proliferation occurs in normal cells in the spleen's parenchyma or stroma.
This usually happens in response to some stimulant that may not be known (called. idiopathic cases) or known (most often antigenic stimulation, increased phagocytosis, e.g. with autoimmune anemia or parasitic diseases).
The nodules are spherical or irregularly shaped, single or multiple, of various sizes - from a centimeter to several dozen centimeters and of various colors:
- in the case of predominance of cells of the lymphoid lineage - white, gray or lard-like,
- when the cells of hematopoiesis dominate or the red pulp is proliferating - the nodules are red or cherry red.
Nodular hyperplasia of the spleen is usually asymptomatic, and nodules are often diagnosed accidentally during abdominal ultrasound or laparotomy.
However, nodular hyperplasia may manifest itself clinically, e.g. in a situation where a hematoma forms within the hyperplasia (symptoms of abdominal pain or symptoms of vascular collapse may then be visible).
Removal of a hyperplastic nodule or splenectomy results in a full recovery, and the prognosis in dogs after surgery is favorable.
Extramedullary hematopoiesis is the production of cells of the hematopoietic system. It is usually seen in older animals.
Blood clots or spleen infarctions
They are associated with blood coagulation disorders. Therefore, they can be found in the course of neoplastic diseases that cause coagulopathies.
Neoplastic diseases that can cause foci to form in the spleen
Benign neoplasms of the spleen are found relatively rarely.
Hemangiomas (haemangioma), lipomas and, exceptionally, tumors composed of adipose tissue and extramedullary hematopoiesis (myelolipoma) are possible.
Benign lesions usually do not manifest themselves clinically, which may be the reason for their uncommon recognition (and this, in turn, may translate into their "alleged" rare occurrence).
Only in the case of hemangiomas the tumor may rupture with slow blood oozing and symptoms of anemia or massive hemorrhage with rapidly deteriorating clinical condition of the patient.
Benign stromal tumors of the spleen are extremely rare and are mainly lipomas and leiomyomas.
These are benign changes that cannot be macroscopically distinguished from sarcoma hemangioma.
As a rule, it is necessary to perform a splenectomy and a histopathological examination of the tumor.
Hemangiomas take the form of spherical or oval, usually single tumors, 0.5-3 cm in diameter and red to black in color.
Myelolipoma, or myelipoma
It is also a benign nodular lesion consisting of hematopoietic tissue (hematopoietic elements of the bone marrow) and normal, mature adipose tissue. These lesions may be single or multiple, they may be surrounded by a connective tissue bag.
Myelolipomas in the spleen are rarely diagnosed, most often in the course of other tests. As a rule, they do not show clinical symptoms.
Usually, tumors are hyperechoic. Big changes can crack.
The pathogenesis of myeloblastoma is unknown, most likely it is a metaplasia lesion. The diagnosis of myelolipoma is based on a histopathological examination.
Myelolipomas are benign changes, removal of the tumor leads to complete recovery.
Malignant neoplastic processes that affect the spleen can lead to the appearance of nodular changes in the organ (nodular splenomegaly) or to uniform enlargement of the spleen (diffuse splenomegaly).
Among nodular lesions, the most frequently diagnosed malignant neoplasm in dogs is hemangiosarcoma, and less frequently, sarcomas originating from cells forming the spleen stroma and histiocytic sarcomas.
Other types of malignant tumors and benign spleen tumors are rare in animals.
Spleen and liver angiosarcomas are highly metastatic and malignant vascular tumors (tumors of the blood vessels) that arise from endothelial cells, the cells that line the inner surface of blood vessels.
HSA is formed as a large mass that develops in the liver or spleen, spreading rapidly through the blood, most commonly to the liver (from the spleen) or to the lungs (from the spleen or liver).
It can also lead to the development of proliferative changes in the network.
In some cases, it causes metastases to the brain or heart.
Hemangiosarcoma is most often visible as a solid cavernous lesion within the spleen. About 25% of dogs have changes to the right atrium at the same time.
Some of these dogs are brought to the vet with signs of collapse due to cardiac tamponade, resulting from the bleeding of the atrium lesion.
These tumors grow as gray or red black, single or multiple nodular structures of varying sizes.
In the right atrium in dogs, they are most often single tumors, but multiple lesions have also been reported.
In the skin, the tumor appears as round or oval, raised, aboveground hard tumors, usually without ulcerations.
The surrounding skin may show ulceration and haemorrhage, and the epidermis may show signs of hyperkeratosis. If they penetrate deeply into the subcutaneous tissue and muscles, they can lead to painful swelling or cause lameness.
Blood clotting disorders, such as intravascular coagulation syndrome or thrombocytopenia, and anemia are common in dogs with HSA.
Hemangiosarcoma is common in older large breed dogs, especially German Shepherds.
The prognosis is poor.
They do not come from lymphoid tissue or blood vessels, but from various elements of connective tissue.
This group includes:
- spindle cell sarcomas, such as fibrosarcoma,
- sarcoma leiomyomas (leiomyosarcoma),
- histiocytic sarcomas (sarcoma histiocyticum),
- undifferentiated sarcoma (sarcoma indifferentiatum).
They most often appear in the form of single nodules protruding above the surface of the organ.
Spleen stromal tumors (originating in the cells that make up the stroma of the spleen).
Due to the spindle-shaped, elongated shape of neoplastic cells, they are classified as. spindle cell tumors. Spindle cell sarcomas account for 13 to 34% of spleen neoplasms.
As they are characterized by various microscopic images, immunohistochemical examination is often necessary to differentiate them. The vast majority of them are malicious.
Stromal tumors occur in dogs of all ages (average 10-11 years), but they are found even in 3-year-old dogs.
Golden Retriever, Labrador and German Shepherd dogs appear to be more likely to develop these cancers, but it is recognized that there is no racial predilection.
Clinical symptoms may include:
- enlargement of the abdominal wall, which may be due to the presence of a tumor and / or ascites),
- lack of appetite,
- weight loss,
- increased thirst,
Symptoms are vague and the disease progresses rapidly, so most dogs are advanced disease when diagnosed and approximately 70% already have metastases to other internal organs.
The presence of a tumor can often be detected during palpation and ultrasound examination of the abdominal cavity, as well as using X-ray and computed tomography.
The diagnosis is made on the basis of the histopathological examination of the tumor.
The most common form of these tumors is fibrosarcoma, which in one study accounted for 23% of malignant stromal tumors.
17% of malignant stromal tumors (leiomyosarcoma) accounted for.
Rare forms of spindle cell sarcoma in the spleen of dogs include:
- undifferentiated sarcomas, which constitute up to 1/4 of the spindle cell tumors of the spleen.
It is the third most common malignant neoplasm of the spleen, which has a nodular form.
It is derived from interstitial dendritic cells.
The tumors are most often multiple and dispersed throughout the spleen.
Most often, histiocytic sarcoma of the spleen is the result of generalization of the neoplastic process from a different location - tumors are then present in other organs of the abdominal cavity and / or in the chest organs.
A specific (and rare) type of histiocytic sarcoma is its haemophagocytic form, in which cancer cells cause phagocytosis of red blood cells.
This tumor originates from spleen macrophages and usually causes diffuse splenomegaly (does not form tumors). The predisposed breeds include:
- Bernese Mountain Dogs,
- golden retrievers,
- flat coated retrievery.
Many tumors can metastasize to the spleen.
Non-cancerous diseases that most often cause uniform enlargement of the spleen
Diffuse splenomegaly of non-neoplastic background is most often associated with systemic diseases and is one of the elements of the general process.
Most often, uniform enlargement of the spleen occurs due to the accumulation of blood in this organ in the course of splenitis.
It is accompanied by active hyperemia and an influx of inflammatory cells to the spleen. The most common causes of spleen inflammation:
- viral diseases:
- bacterial diseases:
- Pseudomonas infection,
- parasitic diseases:
- fungal infections:
The second common cause of spleen enlargement - resulting from passive hyperemia - is blood stagnation in this organ.
Right-sided heart failure or liver failure can lead to portal hypertension and blood stasis in the spleen. Common causes of blood stagnation in the spleen:
- use of barbiturates,
- spleen torsion - rare unless associated with the dilation and torsion of the stomach
- hemolytic anemia,
- failure of general and local circulation.
Less commonly, diffuse splenomegaly is the result of a non-neoplastic proliferative process in the spleen (e.g. growth of lymph nodes) or extramedullary hematopoiesis; occasionally, it may also be a consequence of the accumulation of pathological substances in it, e.g. amyloid deposits in amyloidosis.
Extramedullary hematopoiesis in the spleen may be idiopathic (of unknown cause) or may be the result of the body's increased demand for blood cells (when the bone marrow's blood-forming capacity is exceeded).
Hematopoiesis in the spleen with the dominance of red blood cell formation is most often accompanied by:
- anemia (often autoimmune haemolytic),
- chronic circulatory failure,
- lung diseases.
Hemopoiesis with the predominance of granulocyte production (myelopoiesis) is observed in inflammatory diseases (e.g. pyomatous in bitches).
Myeloid metaplasia in the spleen
It can accompany various proliferation processes of myeloid cells (e.g. bone marrow fibrosis, myelodysplastic syndromes or bone marrow tumors).
Characteristics of the breed
Certain breeds of dogs, e.g. German Shepherds may have a larger spleen than you might expect given their size.
Neoplastic diseases that can cause generalized enlargement of the spleen
Generalized enlargement of the spleen due to neoplastic causes is most often observed in cases of secondary involvement of this organ by the neoplastic process. This is the case, for example, in the course of:
- multifocal lymphomas,
- disseminated mastocytoma,
- histiocytic sarcoma.
As a rule, these diseases are not limited to the spleen alone.
The most common primary neoplasm of the spleen in the form of diffuse splenomegaly is marginal zone lymphoma.
Malignant lymphomas (lymphoma malignum) arise from lymphocytes.
Spleen enlargement and neoplastic hyperplasia usually appear in the multifocal form of lymphoma (the presence of lymphoma in various organs is simultaneously referred to as multifocal form) and then the lesions also affect the lymph nodes, liver and bone marrow.
Liver or spleen involvement is synonymous with the diagnosis of stage IV clinical disease.
The involvement of the spleen is most often secondary to aggressive lymphomas, e.g. lymphoblastic lymphomas or diffuse lymphomas from large B lymphocytes.
Spleen lymphomas occur mainly in the form of diffuse enlargement of the spleen, but a process limited to this organ is rarely observed - much more often it spreads to the spleen from other places.
In the case of advanced lymphoma, the clinical picture is varied, non-specific gastrointestinal symptoms and disorders of the haematopoietic system may occur.
Chemotherapy is relatively effective in spleen lymphomas, while splenectomy is not performed frequently.
These tumors occur primarily in older dogs (8-13 years of age), mostly male.
The spleen occupied by lymphoma is most often evenly enlarged (significantly), heavy, and its edges are rounded. The consistency of the organ can be stout or, on the contrary - brittle and soft, and in extreme cases it can crack.
Changes in the form of large, single or multiple tumors are less common.
On ultrasound examination, the spleen is usually enlarged, the echogenicity of the parenchyma may be lowered or increased, and the echostructure is heterogeneous. The most common presence in the parenchyma is the presence of multiple, diffuse hypoechoic nodules giving the image of "honeycomb " or "Swiss cheese ".
Spleen enlargement is seen in approximately 70% of dogs with centroblastic lymphoma (the most common in dogs).
Aggressive forms of T-cell lymphoma, affecting only the liver, spleen, and bone marrow are much less frequently reported in dogs. They cause an unfavorable prognosis.
Primary spleen lymphomas are rare in animals. These are mainly lymphomas from the marginal zone of lymph nodes (about 10% of all lymphomas in dogs) and (extremely rarely) mantle cell lymphomas.
Marginal zone lymphomas are classified as "peripheral B cell neoplasms, marginal zone ".
This type of lymphoma can affect the lymph nodes, the spleen, and the lymphatic tissue associated with the mucous membranes (mainly the intestines, tonsils, respiratory tract). It is most often found in 8-9 year old dogs without any breed or gender predilection. As a rule, it is detected accidentally during palpation of the abdominal cavity or ultrasound examination.
Lymphoma most often takes the form of hypoechoic focal lesions, rarely diffuse splenomegaly. In extreme cases, the spleen may rupture, resulting in bleeding into the abdominal cavity and anemia associated with it.
The diagnosis is made on the basis of histopathological examination of the tumor that was surgically removed. The prognosis for marginal zone lymphomas is favorable - usually only the spleen is involved and splenectomy is a sufficient treatment.
Leukemia - Peripheral lymph nodes do not need to be enlarged
In addition to splenomegaly, hypercalcemia, gammaglobulinemia and bone changes are also found.
Mast cell tumor metastasis
The spleen is a common site for canine mast cell tumor metastasis. It is one of the most common forms of skin cancer in this species.
Most poorly differentiated tumors are highly infiltrating lesions with a high probability of metastasis to the surrounding lymph nodes, liver, spleen, bone marrow and other organs, including the skin.
The more severe primary tumors are ulcerated, bleeding lesions with satellite nodules around the primary site that can cause paraneoplastic vomiting, tarry faeces, or shock.
In such cases, symptoms of an enlargement of the surrounding lymph nodes or the liver and spleen may be observed. Then the treatment is based on chemotherapy in the form of vinblastine with prednisolone or lomustine.
Diffuse (malignant) histiocytosis
Histiocyte diseases are a complex group of macrophage diseases found in different places in the body.
Some of them can also attack the spleen.
The spleen may have primary or disseminated histiocytic sarcoma known as malignant histiocytosis.
Malignant histiocytosis is a rare disease.
May affect most dog breeds, but is clearly represented among Bernese Mountain Dogs at risk of 600 times higher than other breeds.
An increased risk of developing the disease has also been reported in flat coated retrievers, rottweilers and, to a lesser extent, golden retrievers.
Polycythaemia Vera - overproduction of red blood cells leads to enlargement of the spleen.
Spleen tumors are most common in middle-aged and older dogs. It is especially important to distinguish a spleen hematoma from a hemangioma and a hemangiosarcoma.
They can all cause bleeding and blood in the abdomen leading to shock, but have a completely different prognosis and can only be distinguished from each other by a pathologist.
Spleen hematoma and nodular hypertrophy are the most common non-neoplastic lesions found in the spleen, accounting for 20-41% of all splenic lesions. These are benign lumps / masses of a clotted blood. Their surgical removal results in a cure.
Hemangioma and angiosarcoma
Both tumors arise from blood vessels of the red pulp and are a group of wildly proliferative abnormal blood vessels.
Eventually, the growth breaks and the spleen bleeds.
Life-threatening blood loss can occur when a blood organ such as the spleen bleeds.
If angiosarcoma is diagnosed, the prognosis is poor, but you will learn about it later in this article. For now, let's get acquainted with the most common clinical signs that are observed in dogs with spleen tumors (including angiosarcoma).
Symptoms of tumors on a dog's spleenSymptoms of tumors on a dog's spleen
Diseases that affect the spleen can be difficult to diagnose and can range from severe shock due to hypovolemia to the accidental detection of lesions in a perfectly healthy looking dog.
The symptoms associated with spleen tumors can be subtle and may only include mild weakness.
Dogs can have a spleen tumor for months and never show any signs until the tumor ruptures.
Within hours, an animal's behavior can change drastically from being active to utter apathy.
In many patients, a tumor can rupture simply because it has become too large.
Most of the splenic masses are highly vascularized, and when they burst, they begin to bleed. If such a tumor bursts and there is profuse internal bleeding, the symptoms are sudden and obvious - e.g. collapse and sudden death.
Earlier signs may indicate the development of shock and include:
- pallor of the mucous membranes,
- rapid breathing,
- poor heart rate.
The patient may be hyper- or hypothermic.
If an animal is in shock it is critical that you notify your veterinarian immediately so that emergency treatment can be started.
If bleeding stops on its own, you may notice that you feel better the next day or even hours later. If the tumor has not ruptured, the signs may be few and weak.
The only symptom may be slight abdominal pain and an increase in abdominal shape.
The exact symptoms will depend on the site of the original tumor (liver, spleen, heart, skin, bones, etc.) as well as where possible metastases have occurred (in the case of malignant processes).
Early stages of the disease:
- abdominal discomfort or pain, possibly a distended abdomen
- loss of appetite - anorexia usually starts mildly and progresses with tumor growth;
- weight loss;
- progressive lethargy;
- exercise intolerance (usually mild);
- progressive or intermittent weakness, often with seemingly spontaneous recovery;
- bright gums;
- possible increase in respiratory rate and respiratory effort.
Late symptoms that appear as the disease progresses:
- persistent early symptoms;
- visible lumps on the head, legs, face, ears, muzzle, back, ribs, abdomen, sides or other places;
- isolating oneself;
- distended and painful abdomen;
- difficulty breathing (panting, rapid breathing, "catching" breath with difficulty);
- black tarry stool possible;
- inability to get up;
- fainting or weakness;
- the presence of fluid in the abdominal cavity;
- palpable mass in the abdominal cavity;
- sudden collapse (usually without any symptoms).
Crisis - Immediate Veterinary Treatment Needed Regardless Of Spleen Disease:
- vocalizing (whimpering, crying) from pain; vocalization that is unusual for your pet may indicate that the pain has become too much; if your pet is vocalizing due to anxiety or pain, consult your veterinarian immediately.
- difficulty breathing (shortness of breath, respiratory failure) due to internal bleeding from ruptured tumors that have spread to the chest;
- abnormal heart rhythm and / or increased heart rate, weak pulse;
- muffled noises above the heart;
- widening of the zygomatic vein;
- enlargement of the liver (hepatomegaly) and / or enlargement of the spleen (splenomegaly);
- pale mucous membranes (especially visible on the gums);
- polyuria (passing too much urine);
- excessive thirst and water consumption (polydipsia);
- blood coagulation disorders;
- prolonged seizures;
- uncontrolled vomiting, diarrhea;
- sudden collapse;
- profuse bleeding - internal or external;
- lameness, limping;
- joint swelling;
- sudden death; it usually results from uncontrolled bleeding caused by a rupture of the tumor.
Non-trauma abdominal haemorrhage may not always be a consequence of bleeding from the spleen tumor, especially if it occurs in a small or medium breed dog.
Spleen bleeding accounts for slightly more than half (58%) of all cases of spontaneous haematemesis and is more common in large dogs than in small dogs. In the latter, the presence of blood in the abdominal cavity is not synonymous with the presence of a malignant tumor of the spleen.
The case is different with large dogs; if spontaneous bleeding into the abdominal cavity is diagnosed in a large dog, it is usually the result of spleen pathology, usually the presence of HSA (in 67% of cases).
Diagnosis of tumors on the dog's spleenCancer diagnosis in dogs
Spleen tumors, usually found in older dogs, can be life-threatening.
They pose a risk of spontaneous rupture, so it is important to get a quick and accurate assessment before starting treatment.
Spleen tumors are usually diagnosed by a combination of hematology and imaging studies.
Clinical evaluation is made using various diagnostic tests, such as:
- blood test,
- Chest x-ray,
- abdominal ultrasound,
- urine analysis,
- coagulation profile,
- analysis of fluid obtained from the abdomen, etc.
Thanks to these methods, it is possible to identify and characterize tumors in the abdominal cavity, demonstrate the presence of free fluid or blood, and any evidence of tumor spread, as well as assess the patient's clinical condition and detect possible accompanying diseases.
Since in some dogs angiosarcoma may also appear in the heart, echocardiography may also be recommended.
Tests used to evaluate the dog's spleen
In the history, particular attention is paid to the possibility of contracting a tick-borne disease, past episodes of collapse and other clinical symptoms that may accompany general diseases.
The veterinarian will ask many questions regarding the development and progression of the disease.
All information regarding the appearance of symptoms, their duration and circumstances is very important.
You should inform the doctor about your dog's appetite and behavior, especially if there are any changes in him. It is also important whether the animal has recently had skin lesions removed that might have metastasized to the spleen.
If your dog has been involved in a traumatic event or has had a sudden onset of clinical signs suggesting internal hemorrhage, it may require immediate stabilization (IV fluid administration, blood transfusion, oxygen therapy).
It includes, inter alia:
- Assessment of the cardiovascular and respiratory systems.
Hemangiosarcomas in the heart can produce symptoms related to cardiac tamponade or fluid in the pericardial sac, such as:
- suppression of heart tones,
- arrhythmia or symptoms of right ventricular failure.
- Examination of peripheral lymph nodes.
- Some cancers show enlarged lymph nodes.
- Examination of the mucous membranes for the presence of petechiae (caused by possible anemia or thrombocytopenia).
Pale mucous membranes may indicate anemia.
- Abdominal palpation for pain, masses and fluid.
A lump in the spleen area may be palpable on routine physical examination.
- Temperature measurement.
- Examination of the skin for primary tumors that may metastasize to the spleen.
- Ophthalmological examination for the presence of lymphoid deposits, haemorrhage, or any other changes in the retina that may be associated with excessive blood viscosity syndrome (found in multiple myeloma, leukemia and polycythemia).
These tests are performed to detect anemia, assess kidney and liver function before anesthesia, and assess the levels of oxygen and electrolytes in the blood.
All these tests are important in determining whether the animal is stable prior to anesthesia and surgery, or whether measures are necessary to stabilize the patient's condition (e.g. Blood transfusion).
Complete blood count with smear evaluation.
Complete blood count does not show any specific abnormalities that would clearly indicate a spleen tumor, but may give clues such as. unexplained anemia.
Findings can include anemia or a low platelet count.
In one study of spleen angiosarcoma, most dogs exhibited anemia, thrombocytopenia, and abnormal red blood cell morphology.
Complete blood count may show regenerative anemia, with peripheral blood erythroblasts and reticulocytes, thrombocytopenia and leukocytosis (worsening of extramedullary hematopoiesis).
There may be spherocytes, schistocytes, and acanthocytes in the blood smear. This is due to the microangiopathy associated with HSA. Such a microscopic image may suggest a spleen tumor.
Thrombocytopenia may occur secondary to the tumor or due to intravascular coagulation.
The hematocrit and total protein should also be assessed. If a spleen tumor ruptures, the patient usually has low hematocrit and sometimes also low protein.
Secondary spleen diseases such as leukemia, lymphoma, autoimmune anemia, and certain parasitic diseases (e.g. Babesiosis) can be diagnosed on the basis of hematological examination.
Blood chemistry to assess the function of the kidneys, liver and pancreas. The biochemical profile may show hypercalcemia, hyperglobulinemia and / or hyperbilirubinemia.
Electrolyte profile to exclude dehydration or fluid and electrolyte disturbances.
Assessment of blood clotting is also important.
Other laboratory tests
- Blood test for tick-borne diseases.
- Determination of thyroid hormone levels.
- Urine testing to check for urinary tract infections or other conditions, and to assess your kidney's ability to concentrate urine.
- Stool examination to rule out intestinal parasites.
- ECG to check for an abnormal heart rhythm that may indicate heart disease.
- Bone marrow aspiration.
X-ray and ultrasonography allow to detect the presence of nodular changes in the spleen and fluid or blood in the abdominal cavity or the pericardial sac, but they do not allow for a clear diagnosis of what type of tumor we are dealing with.
Ultrasound examinations of the abdominal cavity and chest X-rays allow for the possible detection of metastases from the spleen tumor (especially angiosarcomas are characterized by a high tendency to spread).
However, even finding other nodular changes apart from the spleen, e.g. in the liver - although it strongly suggests dissemination of the malignant process - it does not yet determine the malignancy of the spleen tumor.
Indeed - the coexistence of focal lesions in two organs at the same time is often associated with tumor dissemination (in 48% of cases this is the case).
However, in 27% of dogs with concomitant tumors in the spleen and liver, a benign process was diagnosed at both sites.
Therefore, imaging tests, such as X-ray or ultrasound should never be the basis for the diagnosis of a malignant tumor. Diagnostic imaging is one of the methods of determining the initial diagnosis that should be confirmed (or excluded) on the basis of the histopathological examination of the tumor.
X-rays of the abdominal cavity may show masses of the spleen or an enlargement of the shadow of this organ.
You may also see fluid or blood in the abdomen.
Chest x-rays are often performed to detect the tumor has spread to the lungs (metastases). Chest X-rays also show the presence of disorders, such as features of right-sided heart failure.
Screening images of the abdominal cavity and / or chest may also be necessary if the animal has been involved in a traumatic event, e.g. traffic accident. The aim of the examination is then to detect injuries to the ribs, diaphragm, lungs or other organs.
Ultrasound examinationUltrasound examination
If there is a lot of fluid or blood in the abdomen, X-rays will be difficult to interpret as the fluid obscures the view of other structures in the abdomen. In this case, ultrasound of the abdominal cavity is very useful to identify masses or other abnormalities of the spleen and other organs.
An abdominal ultrasound examination can identify abnormal spleen tissue, detect enlargement of this organ, the presence of nodular lesions and the presence of fluid / blood in the abdominal cavity.
Additionally, under ultrasound control, a spleen biopsy is performed to obtain material for examination.
Ultrasound is also used for pre-operative evaluation of spleen tumors and hematomas associated with neoplastic or non-neoplastic diseases (e.g. twist of the spleen or lobe of the liver, trauma, dilation and torsion of the stomach, or liver and biliary disease).
An abscess usually takes the form of rare solid or cystic lesions, single or multiple, hyperechoic to heteroechoic.
Hematoma may be traumatic or accompany neoplastic changes (usually angiosarcoma, lymphosarcoma). It can be internal, subcapsular or external, after perforation of the spleen capsule with free fluid around, initially hyperechoic.
During extravasation, the hematoma is aechogenic or hypoechoic, with time a clot forms and becomes more hyperechoic.
Clot lysis reduces echogenicity again.
The further organization of the hematoma increases the echogenicity of the focus.
The presence of an aechogenic fluid is also possible.
It is usually impossible to distinguish a hematoma from a tumor, especially since both lesions can occur simultaneously.
With benign nodular hyperplasia, single or multiple tumors of different sizes with different echogenicity may be visible. Diagnosis is possible based on the exclusion of other changes.
The most common image of splenic angiosarcoma is nodular splenomegaly with the presence of single or multiple lesions, however, the structure of HSA in the ultrasound image may be very variable.
It can take the form of single or multiple, focal, solid, solid with cavities, hematomas, usually hypoechoic or heteroechoic (less often hyperechoic) tumors.
These lesions are gray or reddish in color, show slow growth and at the time of diagnosis reach sizes from a few millimeters to several centimeters.
Often in the tumor mass, necrotic foci and haemorrhages are found.
There may be signs of inflammation, perforation, or the presence of free fluid around the tumor.
In one study, the maximum lesion size significantly differed between malignant and benign tumors. There was also a correlation between the tumor margin and the type of spleen tumors.
In this study, it was observed that a large spleen tumor size is likely to indicate a malignant tumor, and that a large tumor size poses a risk of hemorrhage due to spontaneous rupture and the possibility of metastasis.
Dogs with mild spleen weights have also been shown to have a higher volume-to-spleen weight ratio and a higher spleen weight as a percentage of body weight than dogs with hemangioma.
However, measuring body weight will not help distinguish benign processes from non-HSA spleen malignancies.
Doctors are more concerned about the possibility of angiosarcoma when the mass of the spleen appears cavitated (i.e., containing cavities).
Abscesses, angiosarcomas, hematomas and hemangiomas can cause cavernous lesions visible on ultrasound and should not be performed with fine needle biopsy.
It can be difficult to distinguish the type of spleen tumor on the basis of ultrasound, because the ultrasound images are sometimes ambiguous. Malignant and benign tumors may look similar, and tumors of the same histological type may differ significantly in their echogenicity.
Since ultrasound does not distinguish between benign and malignant tumors, an ultrasound-guided biopsy should be performed to determine the nature of the mass.
Unfortunately, this is not always advisable (cavernous puncture should be carried out with great care, and many doctors do not take the risk of a biopsy in such situations). In addition, the sample usually has to be sent to a pathologist and it takes anywhere from 3 days to even 2 weeks to get results.
Complications that may occur after a biopsy include hemorrhage and "spreading" of cancer cells.
Ultrasound is sensitive to subtle changes or abnormalities in the structure of the spleen, but its ability to assess specific diseases is limited.
The accuracy of imaging diagnosis has been significantly improved with the development of computed tomography, which is now increasingly used in veterinary medicine.
Studies of the spleen of dogs using a CT scan have shown that in hemangiosarcoma tumors are usually larger than undifferentiated hematomas and sarcomas of the spleen, however, the size of the tumor and its echostrukutra cannot be a differentiating factor.
One study showed that suppression of precontrast lesions in most malignant spleen tumors was lower than 50HU in CT scans.
The examination with the use of spiral tomography and magnetic resonance imaging can be diagnostically valuable, especially in the assessment of the tumor structure and in the differentiation between different types of benign and malignant changes. However, these methods are not yet sufficiently common in veterinary medicine.
Magnetic resonance imaging
The use of magnetic resonance imaging can increase the accuracy of the diagnosis of a spleen tumor in dogs.
Earlier human study showed that the use of MRI is superior to contrast-enhanced computed tomography for detecting and characterizing spleen lesions.
In the MRI study of focal lesions of the spleen and liver in dogs, the overall accuracy in differentiating malignant from benign tumors was 94.3%.
If changes in the spleen are found, an ultrasound examination of the heart is also recommended. Echocardiography is indicated in the following situations:
- an ultrasound examination of an enlarged spleen that may be due to right heart failure,
- in patients with symptoms of pericardial fluid,
- when the presence of tissue hyperplasia in the right atrium is suspected (in 25% of HSA cases),
- The ultrasound of the heart can also be used to perform ultrasound-guided fine-needle biopsy,
- during chemotherapy with doxorubicin.
The most common symptom accompanying cardiac angiosarcoma is hydrocardium.
Echocardiography shows a tumor, most often originating in the right atrium.
It is always in close contact with the heart muscle.
Sometimes small tumors cannot be visualized during transthoracic echocardiography, and the only symptom of their presence is fluid in the pericardial sac.
Puncture of the pericardial sac to bleed fluid usually improves the patient's clinical condition, but the hydrocele recurs.
The cause of death in dogs with HSA of the heart is often a cardiac tamponade or a rupture of the atrium.
Surgical removal of the tumor along with part of the atrium and pericardium, and chemotherapy are used to treat this condition. Surgery is difficult and can be effective in dogs that have not metastasized.
Abdominocentesis is often done to check for blood in the abdomen, which may indicate a spleen rupture.
This procedure involves inserting the needle through the abdominal wall and taking a sample of the fluid into the syringe for laboratory testing.
Often, some fluid from the abdominal cavity is also released, especially in patients who suffer from breathing problems as a result of ascites or large volumes of blood abdomen.
Analysis of tissue taken directly from the tumor is the most conclusive method of diagnosis and may provide additional data useful in identifying the type of spleen tumor.
The diagnosis can often be made by ultrasound-guided fine needle aspiration (FNA) biopsy of the spleen, but the samples collected in this way are very often contaminated with blood.
Additionally, when performing a fine needle biopsy, there is a risk of tumor dissemination / infection to the abdominal cavity.
Some specialists suggest that you should not biopsy the cavernous lesions of the spleen found on ultrasound but remove all of them with the spleen, as the lesions are likely abscess, hematoma, or hemangiosarcoma.
On the one hand, it may be difficult to take an appropriate sample for examination (and if malignant lesions are suspected, it is of great importance) without the whole spleen being excised, on the other hand - if it turns out that it was only a benign lesion, splenectomy as a method treatment may be considered too radical.
Unfortunately, the fine-needle biopsy method is not reliable - in the evaluation of 17 malignant spleen tumors, only 8 results were consistent with the histopathological results.
Additionally - the correct collection of the material for the examination depends on the ultrasound technician's skills - incorrect or incomplete sample collection may be the result of not recognizing malignancy. One of the drawbacks is also the possibility of iatrogenic haemorrhage after the spleen puncture procedure.
Coagulation profile determination may be indicated prior to biopsy by techniques other than fine needle aspiration.
Surgical exploration of the abdomen may not infrequently be required to identify the underlying problem and remove the diseased spleen.
Whether it's benign or malignant?
Perhaps the most important difficulty in the case of spleen diseases is to determine whether the accidental palpation of an enlarged spleen or the detection of changes in this organ during a routine ultrasound examination of an older dog is a cause for concern.
Histopathological examination is considered the gold standard for determining the nature of changes in the weight of the spleen.
The problem, however, is that it is often not possible to say clearly whether the tumor is benign or malignant before splenectomy surgery.
It is not uncommon for dogs in a serious condition to see a doctor shortly after a spleen tumor ruptures, and surgery is then a life-saving procedure.
In the case of surgical removal of the spleen, it will be sent to a laboratory for histopathological examination. In some cases, a less invasive fine needle aspiration biopsy can be performed, which can determine what pathology the patient is dealing with prior to surgery.
Attempts have been made to distinguish between benign and malignant processes based on certain clinical features, such as:
- observed symptoms,
- age of the dog,
- the presence of blood in the abdomen,
- the nature of the splenic mass (especially cavernous tissue),
- tumor size, etc.
Unfortunately, while these several factors may increase the clinical suspicion of a hemangiosarcoma, no feature or combination of outcomes has been found to adequately predict a malignant tumor. As a result, histopathology is usually indispensable.
One determinant of a tumor's malignancy is its spread.
If there is evidence of tumor metastasis, then the tumor is malignant. Therefore, a chest X-ray is performed prior to splenectomy. If it shows lung tumors, it is generally too late for splenectomy to be a meaningful treatment.
If, on the other hand, there is no evidence of tumor spreading, the mass may be mild, or it may simply be too early to detect tumor spreading.
If the histopathological examination shows that the tumor is malignant and the metastases are minimal or absent, chemotherapy may be a reasonable treatment option. Chemotherapy regimens depend on what type of cancer the tumor turns out to be.
Treatment of spleen tumors in a dogTreatment of spleen tumors in a dog
Splenectomy in a dog
The mainstay of treatment of dogs with spleen tumors is surgical removal of the spleen, i.e. splenectomy.
It is used to treat a wide variety of diseases and conditions.
The procedure may be recommended if the dog suffers from:
- spleen ruptures,
- the presence of tumors in the spleen,
- spleen torsion,
- acute expansion and torsion of the stomach,
- spleen infections.
If a lumpy mass is found, splenectomy is preferable to biopsy as it serves both diagnostic and therapeutic purposes.
In a situation where the patient has a rupture of the tumor and hemorrhage into the abdominal cavity, the primary purpose of splenectomy is to stop the bleeding and its harmful effects on the body.
Rescue stabilization of the patient
Ideally, all patients should be stable prior to spleen removal surgery. Unfortunately, this is often not possible in dogs undergoing splenectomy due to the presence of a tumor or tumors in the spleen.
Often the operation itself is performed urgently precisely because the patient is unstable and the procedure becomes life-saving.
The splenectomy operation is performed under general anesthesia.
An incision is made in the abdominal wall and the spleen is removed.
In most cases, the procedure is smooth and does not constitute a high-risk operation. Most often - especially in the case of spleen tumors - the entire spleen is removed, and the organ itself is sent for histopathological examination.
If the dog is severely affected by significant blood loss, the surgical risk increases, so your veterinarian may need to provide initial stabilization therapy with IV fluids, oxygen or blood transfusions. When the patient is stable and diagnostic tests have shown the need for splenectomy, the animal is given general anesthesia and the spleen is removed.
Affected patients are usually anemic and increasing blood oxygen levels can help minimize complications during surgery and recovery.
Monitoring of vital activities
As many dogs with bleeding spleen tumors are severely affected, it is important to monitor all vital signs prior to surgery and during anesthesia.
To ensure that the patient does not develop hypotension, blood pressure is monitored continuously. Colloids such as hetastarch are often used to prevent blood pressure from dropping during the procedure.
Depending on your hematocrit value, you may need a blood transfusion before surgery. As red blood cells carry oxygen, patients are monitored with a pulse oximeter to make sure they are compensating well and are not too hypoxic.
To help oxygenate the body, dogs are given synthetic blood (Oxyglobin). Oxyglobin can also help increase blood pressure.
Continuous ECG recording
Patients may develop cardiac arrhythmias during and after splenectomy and must be monitored with a continuous electrocardiogram.
Cardiac arrhythmias are not a common side effect of splenectomy in humans, but are common in small animals.
Any trauma to the spleen can cause heart problems.
Often, such patients have premature ventricular rhythms.
There are many debates as to why cardiac arrhythmias occur in patients who have had their spleen removed. Dogs with ruptured splenic masses are known to have an increased rate of cardiac arrhythmias, including ventricular tachycardia.
Arrhythmias are believed to occur for the following reasons:
- The spleen releases factors that reduce the function of the myocardium, depressing the heart muscle.
While this theory has never been proven, it is believed to be the main cause of arrhythmia.
- Sympathetic overstimulation.
It is believed to cause arrhythmias in patients with acute trauma or acute gastric dilatation and torsion.
- As spleen masses increase slowly, the shock to the sympathetic nervous system following spleen removal is likely to be limited.
However, removal of an organ may initiate the process leading to cardiac arrhythmias.
Most cardiac arrhythmias caused by splenic complications do not cause serious problems. Many arrhythmias are self-limiting if left untreated.
Complications of splenectomy
A splenectomy is generally a safe procedure. While the prognosis for uncomplicated splenectomy is good, as with any surgery, splenectomy carries a potential risk of complications, including intraoperative or postoperative bleeding.
It is one of the most common complications of splenectomy.
The spleen is supplied by numerous blood vessels that must be ligated or sealed in order to remove the organ. If bleeding occurs, you may need a blood transfusion.
Other possible complications of splenectomy include:
- blood clots,
- inflammation of the pancreas,
- Heart arythmia,
- death during surgery.
Elderly patients or immunocompromised dogs are most at risk of complications following surgery.
Overall, there are few long-term complications after splenectomy.
The functions of the spleen are taken over by the liver and the lymphatic system (lymph nodes). However, it is not known which particular system takes over which function. It is only known that the body compensates for the removal of the spleen without interrupting the functioning of the other organs.
Side effects of a splenectomy in a dog include:
- greater susceptibility to infections,
- exercise intolerance,
- insufficient response to decreased cardiac output,
- decreased response to hypoxia,
- susceptibility to erythrocyte parasitism (dangerous especially in babesiosis).
Whether a splenectomy is necessary?Whether a splenectomy is necessary?
Some owners need to decide quickly to consent to splenectomy as the mass of the spleen is actively bleeding and the dog's life is at risk. There may not be time for detailed investigation before surgery, so it is often unknown whether the tumor is benign or malignant.
There is a high probability that the malignancy will become apparent immediately after opening the abdomen. In such situations, caregivers not only face the decision regarding the procedure, but can also face other, very difficult questions, for example:
- If your doctor determines that a malignant tumor has most likely developed in your spleen after starting surgery, do you want your dog to be put to sleep at that point?? Of course, only histopathology enables the final diagnosis, but many caregivers (knowing the prognosis of a malignant tumor) decide to euthanize the dog at this point.
- Or maybe you want to have your spleen removed to consider chemotherapy?
- Do you just want the incision to close and your dog to wake up?
These questions should - if possible - be answered before surgery so that the veterinarian knows what to do if this happens.
A spleen tumor may also be an accidental discovery during a physical exam, an abdominal ultrasound, or a dog's laparotomy.
The animal may show no signs, or the symptoms may be non-specific, such as, for example:
- lack of appetite,
- weight loss,
What to do in this case? Ignore the mass or remove the spleen?
In these situations, owners may have time to think about options. Reliable statistics are usually helpful in making an informed decision by the caregiver (because he or she ultimately decides).
Retrospective studies were conducted to establish the malignancy rate and survival rate in 105 dogs splenectomized for accidental, non-ruptured spleen tumors.
Patients were identified within 4 years from the medical records of the Boston Veterinary Center. Only dogs with histopathologically confirmed diagnosis were included in the study.
Here are the main results of the study:
- 70% of dogs had benign spleen lesions and 30% had malignant tumors,
- 58% of dogs with malignant tumors had angiosarcoma,
- the median life expectancy of dogs with benign lesions was 436 days (
- the median survival of dogs with malignant lesions was 110 days (
- the mean life of dogs with angiosarcoma was 132 days (> 4 months); median survival time for patients who received chemotherapy was 223 days (> 7 months),
- dogs splenectomized for random spleen weight (no intra-abdominal bleeding) have a better long-term prognosis than symptomatic dogs.
- of 95% of dogs that underwent ultrasound, 41% of the malignant tumors were hypoechoic, which was significantly more frequent than that of benign masses (22%); overall median spleen diameter was 7 cm; benign weights were slightly smaller (median 6.25 cm) than malignant tumors (median 8 cm).
Although spleen nodules were more benign in this study, they can still grow and rupture, causing hemorrhage. This can increase complications and worsen survival rates.
Therefore, early intervention is recommended for any focal lesions in the spleen to limit the development of metastasis and increase the length of survival.
In addition, chemotherapy for malignant lesions of the spleen should be considered.
Despite all spleen functions, dogs can live a normal life without a spleen. Most dogs never experience problems. There are several infections that are more common in splenectomy patients, but the incidence is low.
What if a lumpy lesion is found and the spleen is not removed??
It also happens that ultrasound detects a tumor in the spleen, but the caregivers do not decide to undergo splenectomy.
Regardless of the follow-up, a biopsy of the splenic lesion is significant. Depending on the nature of the tumor, the scenarios may be different:
- If we are dealing with a benign tumor or a non-neoplastic lesion, the prognosis is much better than in the case of malignant lesions.
In general, it is recommended that tumor growth be closely monitored by ultrasound.
Unfortunately, if the tumor grows, at some point it will cause internal bleeding, which is a direct threat to life.
- In the case of malignant neoplasms, the prognosis is poor.
Sooner or later, the dog will experience severe bleeding.
Splenectomy and chemotherapy are the main pillars of the management of angiosarcoma.
After surgery, the dog will need to be monitored and / or treated for anemia, pain, and cardiac arrhythmias.
Depending on the results of the biopsy, your veterinarian may recommend further treatment, such as chemotherapy.
Patients usually return home on the same day or after a few days of hospitalization. Recovery should be noticeable in about 2 weeks.
A diseased spleen and its giant lumps can weigh up to several kilograms in a large dog, so animals after surgery may appear much thinner.
Optimal treatment of splenectomy patients requires a combination of home and professional veterinary care.
Your dog's activity should be limited to short, controlled walks on a leash only during the first two weeks after surgery. Be careful with physical activity and follow your doctor's instructions as spontaneous hemorrhage may occur.
Find a place in the house where the dog can rest comfortably and calmly, away from other pets, active children and busy passages.
During the procedure, a fairly long incision may be necessary (the affected spleen may be really large), so it is extremely important to carefully monitor the postoperative wound for exudate, bleeding, swelling or redness. Dressings should be changed regularly and any irregularities should be consulted with a veterinarian.
Patient may need to wear an Elizabethan collar or special dog clothes to prevent licking the surgical wound.
An iron supplement for your dog may be needed to help the body rebuild blood after it is lost.
In the postoperative period, antibiotics and painkillers will most likely be prescribed. Give all prescribed medications as directed.
Notify your veterinarian if there are any problems with the patient's medication intake and appetite, and if you notice any disturbing symptoms.
Complications that may be related to surgery include:
- Heart arythmia,
- inflammation of the pancreas (often manifested by vomiting).
After surgery, an EKG is recommended to detect arrhythmias. Although they may require treatment, most arrhythmias resolve within 24-48 hours.
Chest radiography and abdominal ultrasound may be recommended every 3 months after first treatment to monitor for relapses.
Prognosis for dog spleen tumors
Long-term prognosis for spleen tumors is different and depends mainly on the results of the histopathological examination.
Often - to rule out the need for surgery - ultrasound guided fine-needle aspiration biopsy, biopsy, or both. After the results are obtained before the procedure, it is possible to estimate the patient's prognosis and determine the optimal treatment method. However, this is not always possible.
In dogs with suspected hemangiosarcoma of the spleen, clinicians are very cautious about having an organ biopsy due to the possibility of inoculating tumor cells along the needle path or causing iatrogenic splenic rupture.
In such situations, splenectomy is a better diagnostic method, and often (unfortunately) - also a therapeutic one.
Benign spleen tumors and non-neoplastic lesions are successfully treated with surgery.
The prognosis for dogs with spleen stromal sarcoma is poor.
The median survival from splenectomy is 2.5-4 months with 80-100% of dogs not surviving one year.
Some dogs undergo intraoperative euthanasia due to the presence and extent of metastases.
Statistically, dogs with no evidence of metastasis to other organs live longer - the median survival time is 9 months.
Dogs with mesenchymoma have a better prognosis - the median survival time is around 12 months, and 50% of dogs survived for more than a year.
Prognosis of spleen tumors in dogs
- single tumor confined to the spleen - median survival time 9 months,
- metastatic tumor - median survival time 1 month,
- best prognosis for mesenchymoma - median survival time 12 months,
- Soft tissue sarcomas survive approximately 4 months after the surgery itself,
- undifferentiated sarcomas, leiomyosarcomas - median survival time 3-4 months,
- the worst prognosis is fibrosarcoma, myxosarcoma, osteosarcoma - median survival time 1-2 months.
Spleen hematoma and hemangiomas, as well as other benign diseases, may have a similar clinical picture and should be distinguished from hemangiosarcoma. Up to 2/3 of dogs with spleen masses have a malignant tumor (2/3 of them are angiosarcoma).
Dogs with a ruptured spleen tumor requiring transfusion are more frequently diagnosed with angiosarcoma. The remaining patients have benign masses that are successfully treated with splenectomy.
Final diagnosis of angiosarcoma is based on microscopic examination of the tumor after surgical removal.
Some cases of angiosarcomas are not detected even in a histopathological examination. One study looked at 35 cases of spleen hematomas in splenectomised dogs. It turned out that as many as 11% of animals had metastases, which indicates that in fact the diagnosed hematoma developed within a hemangiosarcoma undetected by histopathological examination.
Hemangiosarcoma (haemangiosarcoma, HSA, sarcoma hemangioma)Dog's angiosarcoma
Hemangiosarcoma is one of the most difficult and mysterious diseases encountered in veterinary practice.
It is an incurable tumor of vascular endothelial cells.
At the same time, it is a highly invasive, debilitating and rapidly growing type of cancer that frequently migrates to:
- lymph nodes,
To make matters worse, it is relatively common in dogs; This type of cancer is estimated to account for 5-7% of all tumors seen in dogs.
Sarcomas are cancerous tumors that arise from cells:
- blood vessels,
- connective tissue,
Angiosarcoma is a special type of sarcoma that arises from the cells that line blood vessels, especially smaller arteries and veins.
Since these tumors involve an abnormal growth of blood vessel tissues, they tend to bleed profusely when they are damaged in any way. They are therefore particularly fragile masses, prone to cracking and causing internal bleeding that can be extremely dangerous - and often fatal - to the affected animal.
Spleen HSA is very aggressive, so it grows rapidly and metastasizes, meaning the chances of it spreading to other places in the body at the time of diagnosis are very high (80%).
This tumor can spread anywhere in the body due to the proximity of blood vessels (i.e. to the liver, lungs, brain, organs in the abdominal cavity).
Unfortunately, we do not know what causes or predisposes animals to develop this type of cancer, but some genetic predisposition is believed to exist as German Shepherds, Golden Retrievers, and Labradors are over-represented.
Occurrence of HSA in a dog
Unlike other cancers, hemangiosarcoma is actually an almost exclusive disease in dogs.
In humans, a similar type of tumor (angiosarcoma) is rare due to exposure to vinyl chloride and PCBs in the workplace, such as in rubber and tire plants.
An even smaller percentage of women undergoing high-dose radiation therapy (usually in association with breast cancer) may develop cutaneous angiosarcoma.
Angiosarcomas account for much less than 1% of all human cancers.
Certain mutations are known to predispose laboratory mice to HSA, but it is not known if these mutations contribute to disease in dogs.
Hemangiosarcoma accounts for approximately 7% of all malignancies in dogs.
This tumor can occur anywhere in the body that contains blood vessels, but the most common primary locations in dogs are:
- spleen (40-50%),
- right atrium / heart (10-25%),
- leather (15%).
When it comes to the spleen itself, HSA is the most common spleen cancer in dogs. About 2/3 of dogs with a spleen weight will have a malignant tumor and 2/3 of these tumors are HSA.
Recent studies have shown that 63-70% of dogs with spontaneous hemorrhage (blood in the abdomen following a non-traumatic event) have spleen angiosarcoma.
Hemangiosarcomas can develop anywhere on a dog's body surface, internal organs, or body cavities. Primary tumors are most common in the skin, heart, spleen, liver, and bones.
Heart angiosarcoma is one of the most common heart cancers in dogs.
It appears that any large-breed dog is at a higher risk of developing angiosarcoma, particularly German Shepherds, Golden Retrievers, Labradors, Pointers, and Poodles (e.g. the estimated risk of hemangiosarcoma in golden animals is 1 in 5, reflecting the severity of the problem).
Although dogs of all ages and breeds are susceptible to the disease, it is more common in older or middle-aged dogs (8-10 years of age).
Some statistical data:
- Hemangiosarcoma is the most common malignant neoplasm of the spleen and the most common neoplasm of the spleen in general.
- HSAs account for 23-32% of all spleen lesions in dogs.
- Some studies suggest that HSA is more common in large breed adults:
- 39% of spleen lesions in large dogs,
- 25% of splenic lesions in medium-sized and small dogs
- 65% of malignant tumors of the spleen in large breed dogs,
- 55% of malignant tumors of the spleen in medium-sized and small dogs,
- especially often recognized in German Shepherds and Golden Retrievers.
In Sherwood's study of 325 dogs, no difference in the incidence of malignant spleen tumors was found depending on the size of the dog. It is unlikely that there is a sexual predilection for tumor development, although there are reports of an increased risk of the disease in castrated dogs, in particular sterilized bitches, compared to non-castrated dogs.
Causes of spleen angiosarcoma in dogs
We don't know exactly what causes the disease in dogs.
The actual causes of spleen angiosarcoma, as are the causes of other types of cancer, are not well understood.
The situation is different with skin angiosarcoma in dogs, the development of which may be related to exposure to sunlight.
Observations that the disease is more common in dogs than in other animals and that some breeds are more at risk than others suggest that hereditary factors may play an important role in the pathogenesis of HSA.
Angiosarcoma is a fairly common cancer in some breeds, including Golden Retrievers, Labrador Retrievers, German Shepherd Dogs, Portuguese Water Dogs, Boxers, Dobermans, and English Setters. This indicates that inheritance contributes to the risk and therefore it may be possible to reduce the incidence of angiosarcoma by eliminating the highest-risk alleles from the population.
However, because cancer can develop in any breed of dog, it is believed that interaction of these inherited risk factors with the environment could lead to a spectrum of mutations that result in tumor formation.
Angiosarcoma as a result of genetic mutations
Although cancer is a genetic disease, it is not always hereditary.
Tumor growth occurs when cells accumulate mutations that eliminate the normal limitations of growth and genetic integrity. Thanks to these mutations, cells gain the advantage of selective growth in their environment. This can be compared to an evolutionary phenomenon we call natural selection, albeit on a microscopic scale.
Most mutations arise because the enzymes that control cell division fail.
During cell division, approximately 1 mutation occurs for every ten million replicated bases.
Genomic DNA in dogs is approximately 2.5 billion base pairs. So when a cell divides, it has to copy 2.5 billion bases, so between 250 and 2,500 errors or mutations in DNA will be introduced into each daughter cell.
As some cells in the body keep dividing, replacing others that die or are damaged (e.g. blood, skin and intestine cells), mutations are basically constantly being introduced into cells in the body.
This is why it is said that the greatest risk factor for cancer is "being alive".
Fortunately, most of these mutations are silent (they neither help nor harm the cells or the body), and the system has mechanisms to eliminate most of the cells that acquire harmful mutations.
Stem cells and cancer development
A relatively new concept in the pathogenesis of cancer suggests that only stem cells can cause cancer, making acquiring mutations in somatic cells (any cell that is not a sperm or an egg) less of a problem.
This would mean that simply carrying the mutation does not necessarily mean that the individual will develop cancer, just that the risk is higher.
According to this theory, stem cells may be the only cells that can cause cancer.
Until recently, the dominant theory of the origin of cancer assumed that all cells had an equal capacity for self-renewal - that is, the ability to create a new identical cell that retained all the properties of the stem cell, and that cancer cell proliferation was a random process driven entirely by mutations.
Competitive theory holds that self-renewal is limited to a small population of "cancer stem cells ".
These cells have two characteristics that define "parentage ":
- Multipotency (the ability to create new cells that can differentiate into a single type or lineage).
In other words, a very small number of self-renewing cells in a tumor results in a large number of offspring that make up the majority of the tumor (or tumors).
The existence of "cancer stem cells" is now well documented - they have unique properties of gene and protein expression and the initial transformation appears to involve a relatively small number of mutations.
The accumulation of additional mutations determines the degree to which progeny from these cells will differentiate to give rise to different clinical entities such as aggressive high-grade tumors and low-grade malignant tumors.
This model of carcinogenesis explains why multicellular animals, such as dogs, with trillions of cells in their bodies, can survive most of their lives without developing cancer.
The ability to form cancer is limited to perhaps several hundred "stem cells", which greatly reduces the likelihood that a given cell will accumulate a set of mutations necessary for disease development.
Nevertheless, the high incidence of cancer among the elderly supports the notion that even with a limited number of susceptible stem cells, the likelihood of developing cancer over a long lifetime is quite high. With regard to canine angiosarcoma, recent research confirms that it is a stem cell disease.
Canine angiosarcoma and angiogenesis
Angiogenesis (neovascularization, angiogenesis) is the process of creating new blood vessels.
In this complex, multi-step process, new blood vessels are created from existing ones by budding endothelial cells in the postnatal period.
Angiogenesis continues under physiological conditions, and is intensified especially during embryogenesis, ovulation, pregnancy and during wound healing.
In a healthy organism, angiogenesis is under the constant control of pro-angiogenic and anti-angiogenic factors that are in equilibrium.
Thus, in normal tissues it is a self-limiting process, while in pathologically altered tissues, angiogenesis gets out of control: endothelial cells divide 20-2000 times faster and survive much longer.
Neovascularization is an important element in the pathogenesis of many diseases, for example:
- rheumatoid arthritis,
- gastrointestinal diseases,
- cardiological diseases,
- nervous system infections,
- neoplastic diseases.
This process plays an important role in tumor development, as it enables it to be nourished, growth and metastasis.
The production of new capillaries in a cancerous tumor is referred to as neoangiogenesis.
There are reports that the increase in the formation of new blood vessels in the body may be an indicator of disease activity. Assessment of tumor vasculature is used to establish prognosis, therapy, and assess the effects of cancer treatment.
A much higher vascular density has been demonstrated in malignant neoplasms of the spleen compared to the unchanged parenchyma of the organ. The highest vessel density was found in angiosarcomas with metastases to the abdominal organs (mean 132 vessels / mm2).
It is known that neoplastic tissue is better vascularized, so since tumor growth depends on its vascularization, angiogenesis inhibitors can be used to treat tumors.
Development of angiosarcoma and microorganisms
Recent studies suggest that tick-borne microbes (e.g. Babesia canis, Bartonella spp.).
It was shown that in dogs with pathological changes in the spleen, the prevalence of tick-borne diseases was significantly higher than in dogs with a healthy spleen. In this study, all dogs diagnosed with B infection. canis, HSA was found, although the causal relationship remains unclear.
Symptoms of hemangiosarcoma in a dog
Clinical symptoms of angiosarcoma usually result from intra-abdominal bleeding and more or less severe blood loss, manifested by weakness or symptoms of collapse / hypovolemic shock.
Dog owners with HSA may notice a number of different symptoms depending on where the cancer has developed and the degree of metastasis.
Often, the first signs of a hemangioma are attributed to old age, a change in weather, or changes in the dog's living environment.
However, as the disease progresses, the obvious physical deterioration associated with the tumor usually progresses very quickly. It is not uncommon for caregivers to report that the dog was okay in the morning and, upon returning home, notice that their pet does not even have the strength to stand up.
Most dogs with angiosarcoma are brought to the doctor by their caregivers because of a number of non-specific clinical signs, such as:
- decreased appetite,
- weight loss,
- rapid / difficult breathing,
- abdominal swelling,
- acute weakness / collapse.
These clinical signs are caused by a severe hemorrhage that occurs when a mass in the spleen ruptures and then bleeds. Often these episodes of weakness or collapse are temporary.
Common primary sites of angiosarcoma in dogs are the spleen, the right atrium, and the tissue under the skin.
The "behavior" of these tumors includes infiltration into the normal tissues surrounding the tumor as well as distant spread (metastasis).
The disease is relatively lazy in manifesting any clinical symptoms; in other words, it initially does not cause pain, and the growth rate in the early stages is relatively slow.
Dogs with even large angiosarcomas may not show any clinical signs or evidence that they have a life-threatening disease.
Basically, cancer cells retain some normal aspects of functioning, so when angiosarcoma tumors grow, rapidly dividing endothelial cells try to form blood vessels and vascular channels, but their growth is irregular and abnormal, and the tumors are fragile and prone to bleeding.
These vessels are twisted and distorted, and blood tends to pool and clot in them. The clots then prevent blood and nutrients from entering the cancer cells, which in turn causes them to die.
This results in small cracks appearing in the tumor through which blood can travel to:
- abdominal cavity,
- pericardial sac,
- the chest cavity,
- subcutaneous space.
Depending on the amount of blood lost, affected dogs may show non-specific symptoms such as lethargy and weakness, but these are transient and resolve as dogs absorb blood components and produce new blood cells.
Clinical symptoms recur, but are also subtle enough to go unnoticed for some time.
If bleeding occurs when the tumor is small or the vessels supplying the tumor can be repaired, dogs will usually be asymptomatic. Once the tumor reaches a critical size, the bleeding will usually be more severe and dogs will show symptoms related to massive internal blood loss.
Since hemangiosarcoma tends to aggressively metastasize to the lung, liver, intestines and mesentery (the membranous connective tissue that suspends the intestines), distant spread (microscopic or macroscopic) has inevitably occurred by the time the disease is finally diagnosed.
While it is difficult to say with certainty to what extent a dog with HSA suffers from the disease, reports from people with angiosarcoma and observations from dogs suggest that the tumor usually causes considerable discomfort and pain, especially in the later stages.
In most cases, owners don't have a very good chance of knowing their pet is affected by this type of cancer until it is so advanced that it manifests itself in all its favorite clinical symptoms related to blood loss.
Diagnosis of spleen HSA in a dog
In all cases of suspected hemangiosarcoma, the following should be performed:
- Abdominal ultrasound examination.
- Chest X-ray examination.
If a right atrial tumor is suspected, echocardiographic examination is indicated.
Suspicion of angiosarcoma is made on the basis of history, racial predilection (German Shepherds), clinical symptoms, ultrasound and X-ray examinations, hematological examinations, and possibly abdominal puncture and examination of the collected fluid.
In order to determine the extent of the neoplastic process, and in particular to exclude or confirm the presence of metastatic foci and to establish the prognosis, additional tests are recommended.
Although most spleen tumors are eventually diagnosed as hemangiosarcoma, other types of cancer can occur in this organ, many of which have a more favorable prognosis. One should not draw far-reaching conclusions about the final diagnosis solely on the basis of the presence of tumors in the spleen and liver.
There are cases when the biopsy shows a benign nature of these lesions.
In the differential diagnosis it is necessary to include:
- fibrosarcoma (fibrosarcoma),
- epithelioma (haemangiopericytoma),
- fibrous histiocytoma,
Is there any chance of early detection of a dog's angiosarcoma?
Currently, there is no readily available, effective test for the early diagnosis of hemangiosarcoma.
A blood test may indicate a haemorrhage, and experienced clinicians will "get" suggestions about blood vessel abnormalities by lighting a red lamp with the text "HSA ".
However, this method is neither sensitive nor specific to confirm this suspicion.
Therefore, it is necessary to extend the diagnostics to include imaging tests, which are already more useful in diagnosing the disease.
Ultrasound examination in particular is a moderately specific, though sometimes insufficiently sensitive method. The tumor must be large enough to be clearly visible on the examination. As we know, most patients already have metastases when the tumor is detected…
The entire diagnostic process is complicated by the fact that histopathological material is required to confirm imaging results.
Such repeated biopsies of tumor-bearing tissues (with no other evidence of tumorigenesis) are of little use in ensuring early diagnosis, and given the risks associated with these procedures, this approach is unacceptable.
Finding a diagnostic method that can detect the presence of hemangiosarcoma in predisposed dogs before the tumor becomes a clinical threat could substantially increase the likelihood of treatment success.
Therefore, the search for potential markers of this cancer in the peripheral blood is being carried out. It has been found, inter alia, that the concentration of endothelial growth factor (VEGF) in dogs is higher in the tissues of the spleen with nodular lesions than in the normal parenchyma of this organ.
Professor Jamie Modiano, University of Minnesota oncologist, leads a research project called "Shine On ".
The first step in this study was to refine the blood diagnostic test method for hemangiosarcoma.
Previous studies from the University of Minnesota showed that there are unique patterns of protein expression that can help distinguish hemangiosarcoma cells from normal cells that line blood vessels, even within the tumor.
Cancer cells released from the tumor enter the circulation (e.g.in. cancer metastases). Scientists decided to take advantage of this fact and develop a test that will look for these cancer cells in the circulation.
To do this, cells are labeled with fluorescent particles and passed through a flow cytometer that can analyze tens of thousands or hundreds of thousands of cells in minutes.
The results of these studies showed that it is possible to detect a small but unique population of cells that are more frequently and in greater numbers found in dogs with HSA compared to healthy dogs or dogs with other diseases.
These cells most likely enter the circulation very early in the process of tumor development.
There is, however, an important caveat.
The presence of angiosarcoma cells in the circulation says nothing about where in the body a tumor is likely to develop, as tumors in the spleen, heart, liver, and skin test positive for this test.
This test was not further developed as it was not feasible until recently. The results of this study were published in the journal "Experimental Hematology " in July 2006.
Phase 2 of the "Shine On" project was designed to determine the ability of a diagnostic test to predict relapse in dogs with angiosarcoma undergoing treatment.
The third phase is to determine if a test looking for specific cells in the blood can be used to detect angiosarcoma at an earlier stage before the tumor develops and to implement angiosarcoma prevention by eliminating tumor initiating cells with eBAT.
Another method that allows the differentiation of individual nodular lesions of the spleen is the evaluation of the expression of microRNAs (short RNA fragments regulating gene expression) in spleen samples.
However, in practice, the application of this test may be difficult (material for testing is collected during invasive procedures).
Treatment of spleen angiosarcoma in a dogTreatment of spleen angiosarcoma in a dog
Treatment options for canine hemangiosarcoma are limited, largely because the disease is not diagnosed until the late stages.
Standard management consists of surgery to reduce or remove the primary tumor (if possible) followed by intensive chemotherapy.
In some cases, splenectomy cannot be performed or is impractical or inappropriate (e.g. if there is evidence of extensive metastasis to sites beyond the primary tumor).
The optimal procedure is to take an X-ray of the chest and an ultrasound examination of the abdominal cavity (with a thorough analysis of the liver) and the heart before the surgery. The prognosis is poor if unequivocal changes are found in these organs.
Median survival for dogs treated with surgery alone is approximately 90 days. This time is extended to about 180 days thanks to the introduction of chemotherapy using one of several available protocols.
There are many documented protocols for the treatment of canine angiosarcoma. In practice, several chemotherapy regimens have been used with the use of:
- doxorubicin itself;
- doxorubicin with cyclophosphamide;
- the vincristine + doxorubicin + cyclophosphamide regimen;
- a protocol was also introduced using low doses of cyclophosphamide, etoposide and piroxicam as adjunctive therapy and obtained results similar to the other regimens but with fewer side effects;
- an alternative drug used in HSA chemotherapy is carboplatin administered every 3 weeks for 4 treatments.
All of these drugs are relatively invasive and only a few long-term survival rates have been reported.
Unfortunately, no particular chemotherapy regimen appears to extend life expectancy beyond all other protocols.
Doxorubicin (adriamycin) is the only chemotherapy drug that has been shown to be most effective at treating HSA.
When used as monotherapy, doxorubicin is administered every 3 weeks for a total of 5 treatments, which requires visits to a reference veterinary facility.
Routine blood tests are performed prior to any chemotherapy, and a chest x-ray and an abdominal ultrasound scan are performed periodically or as indicated to make sure that the chemotherapy is working.
Since doxorubicin has a toxic effect on the heart, regular electrocardiographic and echocardiographic examinations are recommended during chemotherapy.
Side effects of chemotherapy
It is important to note that chemotherapy in dogs with spleen angiosarcoma does not cure the disease. Its aim is to slow down the progression of cancer and thus prolong life in comfort.
While cytotoxic drugs are designed to kill rapidly dividing cancer cells, they also have a detrimental effect on normal cells, especially those that divide rapidly, such as:
- the cells that line the intestines,
- hair follicles,
- bone marrow cells.
So the most common side effects are:
- decrease in the number of white blood cells,
- sometimes hair loss.
A reduced number of white blood cells will predispose you to infection. If a dog's leukocyte count drops, antibiotics are introduced.
Overall, dogs experience a good quality of life while on chemotherapy, but:
- side effects (lethargy, vomiting, diarrhea) of chemistry can show up to 1/5 of patients,
- gastrointestinal disturbances 2-5 days after administration of the cytostatics occur in 20-30% of dogs,
- bone marrow suppression occurs 7-10 days after treatment in 15-25% of dogs,
- around 5% of patients have to stay in hospital because of the severe side effects of chemotherapy,
- approximately 20% of dogs receiving doxorubicin chemotherapy may develop irreversible cardiomyopathy due to myocardial damage,
chemotherapy-related deaths are reported in less than 1% of patients.
Most of the side effects are mild and temporary.
Basically, veterinary patients can handle chemicals better than we humans.
Chemotherapy is usually very well tolerated and dogs show a good quality of life during treatment.
If unacceptable side effects occur, the dose of chemotherapy drugs can be reduced as the goal in veterinary chemotherapy is to improve quality, not life expectancy.
In exceptional cases, chemistry is not administered.
Recent studies have shown that the addition of metronomic chemotherapy (i.e., administration of a constant low-dose chemotherapy) after doxorubicin chemotherapy may slightly increase the survival time of dogs with spleen angiosarcoma.
This approach to treatment has emerged as an alternative to conventional cytotoxic chemotherapy, which is based on the use of a specified maximum tolerated dose of the drug.
Metronomic chemotherapy relies on the fact that endothelial cells of blood vessels are very sensitive to continuous exposure to low doses of chemotherapy drugs.
Through anti-angiogenic and anti-proliferative effects on precursors of endothelial cells, it targets the tumor vasculature. It also affects certain immune cells, which make it easier for the cancer to avoid being recognized and attacked by the immune system.
So this newer approach to chemotherapy focuses more on eliminating the blood supply to the tumor and less on killing the cancer cells directly (as is the case with conventional chemotherapy).
Lower doses of cytostatics are used, leading to a much lower risk of side effects.
Various mechanisms for this anti-angiogenic effect of metronomic therapy have been suggested, including:
- Targeting drug-sensitive endothelial tumor cells.
- Inhibition of endothelial cell proliferation and migration, reduced mobilization of circulating endothelial progenitor cells.
- Stimulating the production of thrombospondin-1 and other endogenous inhibitors of angiogenesis.
There is evidence that metronomic dosing of cyclophosphamide (an alkylating agent) is associated with a number of immunostimulatory effects, including a reduction in the number and regulatory function of T cells, activation of dendritic cells, and stimulation of cytotoxic T cells.
Regulatory T cells (Treg lymphocytes) are a subpopulation of CD4 lymphocytes that normally function to keep the immune system under control and prevent autoimmunity.
Tumors present a variety of antigens, including self antigens.
Regulatory T cells are critical to maintaining the immune system's tolerance to self antigens. They are believed to weaken the resistance of cells to tumor-associated antigens and are the main obstacle to successful immunotherapy.
In other words, these cells prevent the endogenous immune system from attacking and destroying the cancer cells. This is undesirable - when faced with cancer cells in the body, the entire immune system should be alerted, not suppressed.
Research suggests that administering metronomic cyclophosphamide or chlorambucil to both humans and dogs with sarcomas selectively reduces the number of circulating Treg cells in the peripheral blood, thereby enhancing the host's immune response and destroying tumor cells.
So, metronomic chemotherapy is thought to alert the immune system to a tumor and boost anti-tumor immunity by inhibiting regulatory T cells.
Several studies have shown increased effectiveness of metronomic chemotherapy in combination with NSAIDs.
The goal of metronomic chemotherapy is to achieve a sustainable, stable disease with an acceptable quality of life, not to reduce tumor volume.
By targeting tumor-critical processes such as angiogenesis and immune defense, it may be more appropriate and less toxic than conventional intravenous chemotherapy.
Sample treatment plan with metronomic chemotherapy:
- after healing the wound, chemotherapy using the AC protocol (doxorubicin, cyclophosphamide) - 6 cycles every 3 weeks (18 weeks).
- oral metronomic therapy (cyclophosphamide or chlorambucil), starting on the second administration of doxorubicin and lasting 6 months.
- chlorambucil 4 mg / m2 daily + a non-steroidal anti-inflammatory drug, e.g. meloxicam 0.1 mg / kg daily;
- cyclophosphamide 15 m / m2 daily + NSAID (meloxicam 0.1 mg / kg m.c.) every day; the drug Endoxan tabl. is available on the market. 50 mg;
For safety reasons, cytotoxic drugs in the form of tablets must not be divided, broken or crushed (the owner is exposed to the aspiration of fine dust from the broken tablet), therefore administration of this drug in dogs may be problematic
A solution may be to administer a cumulative dose but at longer intervals
In smaller dogs, the best solution is chlorambucil therapy (Leukeran - 2 mg tablets make it easier to select the right dose).
The patient's condition should be monitored throughout the course of therapy, although the risk of side effects at such low doses of cytostatics and non-steroidal anti-inflammatory drugs is minimal.
Before starting the administration of drugs, complete blood counts, blood chemistry tests and urine specific gravity tests are performed.
Two weeks after starting treatment, a morphological check-up is performed (risk of bone marrow impairment and possible gastrointestinal bleeding related to NSAIDs).
Urine analysis (with specific gravity) is also necessary for early detection of problems with concentration of the urine, which may indicate renal failure.
Urine should be collected from the dog after watering for 8-12 hours.
The same set of tests is performed 6 weeks after starting treatment, and then every 3 months.
Unfortunately, no other therapy has yet been developed that is effective in treating or controlling spleen angiosarcoma in dogs.
The cells that cause this disease come from the bone marrow.
We do not know yet when (and why) they are located in the organ where the disease will occur.
Importantly, however, prophylactic splenectomy (removal of the spleen to prevent disease development) is unlikely to bring any benefit, as in the absence of a spleen, the transformed cell (or cells) may simply "pass" to another organ.
Also, the spleen is not an organ that you can just get rid of: although dogs can function without it, they will nevertheless have a reduced ability to adapt or respond to various stimuli.
Is it possible to find a drug for hemangiosarcoma?
Given the grim prospects of current treatment protocols, new supportive therapies are being explored. Anti-angiogenesis therapy is a hot area of research given the endothelial origin of the disease.
The possibilities of targeted therapy using inhibitors of growth factor signaling pathways for neoplastic cells are being investigated.
Immunohistochemical staining of spleen angiosarcomas in dogs showed immuno-expression of receptors for VEGF-2 (endothelial growth factor), and in some cases also for PDGF-2 (platelet-derived growth factor), c-Kit receptor and other kinases that may promote the growth of cancer cells.
The use of inhibitors for these signaling particles could in the future be used in the treatment of animals with splenic angiosarcoma.
Most cancers produce the growth factors they need to survive or "force" cells in their environment to do it for them.
One such growth factor is vascular endothelial growth factor - A or VEGF, which acts by binding to specific receptors on hemangiosarcoma cells.
New drugs developed by various pharmaceutical companies are designed specifically to disrupt the signals transmitted by these receptors. Dependence of hemangiosarcoma cells on VEGF signals should make them more sensitive than normal cells to these drugs.
Several groups are working on introducing them to treatment, but the process is slow due to the need for testing and clinical trials.
Promising results from a research project and clinical trial are coming from the University of Minnesota, where a genetically engineered drug called EGF bispecific angiotoxin or eBAT has been developed.
eBAT belongs to a class of drugs called ligand-targeting toxins.
This drug acts on two proteins that are rarely found at the same time in normal cells but are almost always found together in angiosarcoma cells.
Preliminary results of clinical trials using eBAT in dogs showed that the drug almost doubled survival times in dogs with spleen HSA.
The trial was relatively small, with only 23 dogs treated, six of them surviving more than 1.5 years, exceeding long-term survival expectations by about 10%.
Unlike conventional chemotherapy, eBAT did not show any chronic side effects that would make it unacceptable as a treatment for dogs that would be healthy.
This drug is designed to kill the cells responsible for cancer formation, thus stopping the tumors from starting to grow.
Therapies to help treat cancer in your dog
There is information in the English-language literature on the use of certain supplements in the treatment of hemangiosarcoma in dogs.
There have even been clinical trials, the results of which may surprise you.
I 'm-Yunity (Coriolus vesicolor, CV)
Well, a study at the University of Pennsylvania has shown the effectiveness of "I 'm-Yunity " mushroom supplements (in addition to traditional chemotherapy) in increasing survival time in dogs treated for angiosarcoma.
I 'm-Yunity is a polysaccharide extract from the Coriolus vesicolor mushroom.
Coriolus versicolor (CV) is a medicinal mushroom known in China as Yunzhi.
Several classes of compounds that make up its composition are assigned biological activity, but the most important active moiety is peptide polysaccharide (PSP).
PSP is a homogeneous mixture of macromolecules with closely similar physicochemical properties; it is a group of polysaccharides chemically linked to various peptides.
Coriolus versicolor fungus contains two peptide polysaccharides: PSP and PSK, derived respectively from the strain: Cov-1 and CM-101.
Both show immune and anti-tumor restoration activity in vitro and in vivo. PSP has been shown to exhibit interesting pharmacological properties in vitro. Belong to them:
- activation of T lymphocytes, B lymphocytes, NK cells and NKT (natural killer T-cells) lymphocytes, activated by lymphocytes,
- promoting the proliferation and / or production of antibodies,
- stimulation of the production of cytokines such as interleukin 2, interleukin 6, interferons and tumor necrosis factor.
I 'm-Yunity showed anti-tumor activity in tissue culture studies, causing cell cycle arrest and altered expression of apoptogenic / anti-apoptotic and extracellular signaling proteins, resulting in decreased tumor proliferation and increased apoptosis.
In vitro studies have shown that I 'm-Yunity causes dose- and time-dependent inhibition of tumor growth and reduces the viability of HL-60 leukemic cells.
A pilot I / I 'm-Yunity study conducted at the University of Pennsylvania showed a median survival time of 117 days and 199 days for 50 and 100 mg / kg doses of I ' m-Yunity, respectively, in 15 dogs with metastatic angiosarcoma.
These survival times are longer than those for splenectomy alone (median survival time 19 to 86 days) and comparable to doxorubicin-based chemotherapy (median survival times reported 141-179 days).
However, this information should be treated very carefully due to the fact that only a small number of dogs participated in this study. It should also be emphasized that there are currently no published peer-reviewed data from randomized clinical trials comparing I 'm-Yunity with doxorubicin.
Other in vitro studies have shown cytotoxic activity against several tumor cell lines in gastric and lung cancer, leukemia and lymphoma.
PSP also showed antitumor activity in vivo with a significant reduction in tumor size in mice vaccinated with various cancer cell lines (nasopharynx, liver, colon, sarcoma, melanoma, leukemia).
The use of CV extracts has been evaluated in humans as a therapeutic adjuvant for cancer immunotherapy in various solid tumors in numerous human clinical trials in China and Japan, showing an increase in immune cell proliferation, reduction of chemotherapy symptoms, improvement of tumor infiltration by dendritic cells and cytotoxic T cells, and also an extension of the relapse-free periods and an overall improvement in prognosis.
CV Extracts (PSP) are reported to be very well tolerated by dogs and humans with minimal side effects.
Due to the immune stimulating effect of CV extracts, it is possible to reduce the activity of immunosuppressants and such a combination should be avoided.
Yunnan Baiyao is another Chinese herbal medicine that is used for its hemostatic properties and wound healing in humans.
It is often used in veterinary medicine (mainly in China, Japan, but also the USA, Canada) to control bleeding in dogs with angiosarcoma by improving clotting and platelet function.
Yunnan Baiyao is a protected Chinese traditional medicine and the exact herbal formula is a trade secret. The main ingredient is Panax notoginseng root extract, which has shown an interesting effect in research:
- it inhibits the growth and increases the apoptosis of human colon cancer cells in vitro,
- inhibits DNA synthesis and cell proliferation in human umbilical vein endothelial cells in vitro,
- causes apoptosis of the murine neuroblastoma cell line, and also induces antiproliferative and pro-apoptotic effects in a number of cancer cells.
The Department of Clinical Sciences at the University of Florida conducted a study on the effects of Yunnan Baiyao on canine angiosarcoma cell lines in vitro.
This study assessed the activity of Yunnan Baiyao against three canine angiosarcoma cell lines in vitro after treatment with increasing concentrations of the drug.
Time and concentration dependent cell death due to caspase-induced apoptosis has been demonstrated in all three cell lines.
Yunnan Baiyao has been used in veterinary medicine primarily to control bleeding in dogs with angiosarcoma. This supplement may also promote healing.
Holistic veterinarians use 250 mg twice daily for two weeks and one week off or for two months and one month off.
Additional data from clinical trials are needed to support the current dosing regimens of Yunnan Baiyao.
Break periods are offered due to the possibility of elevated liver enzymes with continuous dosing. However, other doctors use a continuous daily dosage of Yunnan Baiyao (250 mg 2 times a day) continuously.
However, this supplement is believed to help dogs anecdotally, but its full clinical trials assessing the effects on dogs with HSA are still ongoing, so the true efficacy and side effects are currently unknown.
There appears to be significant potential for additive or synergistic pharmacological properties of I 'm-Yunity and Yunnan Baiyao in combination with metronomic chemotherapy in patients with metastatic hemangiosarcoma, however, additional data from clinical trials are needed.
It is not known if these herbs can cross the blood-brain barrier.
Owners, upon hearing the diagnosis, often try desperately to find other treatments for canine angiosarcoma, clinging to a variety of alternative and complementary approaches (herbs, cancer diet, bioenergy, supplements, etc.).
This usually follows extensive advertising, e.g. from online sources.
In forums, there are often reports of a dog receiving such and such treatment and surviving longer than expected.
Leading proponents categorically take this as a success and sufficient evidence that their approach is curative for angiosarcoma.
The danger of assigning the healing power of a given preparation after an anecdotal reaction cannot be overstated.
There is no described case where one of these therapies would be consistently effective (or even as good as standard treatment) when tested in a specific group of individuals.
In fact, such treatments can interfere with or even increase the toxicity of chemotherapeutic drugs.
We know that when some tumors are detected early enough, surgery alone, surgery plus chemotherapy, and in some cases even the absence of any treatment can lead to life extension.
In rare cases, the preservation of the tumor itself causes disease progression to be extremely slow and dogs can survive for longer periods of time regardless of the therapy used.
This means that a certain percentage of dogs diagnosed with hemangiosarcoma live for 2.3, 4 years or more, even without aggressive treatment.
Therefore, it is extremely important that owners of dogs who have been diagnosed with cancer understand two things.
- First, veterinarians would never hold back the effective treatment of any disease.
On the contrary, we would happily accept an effective and non-toxic cure for the disease, if only there was one.
We often fall into hurray-optimism ourselves after we learn about some new, "miraculous " medicine. However, in order for such a drug to be considered effective, extensive clinical trials are necessary, in which the effectiveness and safety of a given preparation can be undoubtedly proven.
- The second thing is that there is no shortage of scammers on the internet, preying on the desperation of people who know that a beloved family member is likely to die of a serious, incurable disease.
How to Feed Your Dog with HSA Cancer?
Over the past 10 years, compelling evidence has emerged that one of the keys to creating a better life is in a surprising place: the dog bowl.
Experts admit that one way to deal with cancer is to control what the patient eats. As cancer changes your dog's metabolism, it is important to adjust the diet to meet his new needs.
How cancer changes dogs' metabolism?
A cancer patient uses carbohydrates, proteins and fats in completely different ways than his healthy counterparts.
In many cases, cancer patients show the so-called. cancer cachexia - a condition in which an animal loses weight despite ingesting nutrients. Dogs with cancerous cachexia show a reduced ability to respond to treatment and a shorter survival time.
Changes in carbohydrate metabolism
The most dramatic metabolic disturbances occur in carbohydrate metabolism.
Cancer cells metabolize glucose from carbohydrates in a process called anaerobic glycolysis, which creates lactate as a by-product.
The dog's body must then use up energy to convert this lactate into a usable form.
The tumor gains energy from carbohydrates while the dog suffers a dramatic loss of energy. In a dog that has not yet been diagnosed with cancer, this can be devastating.
The first thing any handler who starts losing weight is to increase the amount of food that a dog starts to do!
If the dog's food is a traditional food containing a lot of cereal grains with a high carbohydrate content, the handler will add the proverbial oil to the fire. The dog is not benefiting from the increase in carbohydrate content, but his cancer is getting the most out of it.
Changes in protein metabolism
Another metabolic change seen in dogs with cancerous cachexia is that the degradation of the protein outweighs its synthesis, resulting in a net loss of protein in the dog's body.
This in turn causes loss of muscle mass and contributes significantly to weight loss.
In addition, the loss of protein causes reduced cellular and humoral immunity, weakening of the digestive tract and hindered and slow healing of wounds.
Changes in fat metabolism
Most of the pounds lost in cancer cachexia are caused by a significant reduction in body fat, which (like protein) is broken down more quickly in a patient with cancer.
However, unlike carbohydrates and protein, increasing dietary fat does not benefit canine cancerous tumors. Fortunately, your dog's ability to use fats as an energy source is unimpeded.
Understanding these metabolic changes can help us formulate a diet that will maximize the benefit of the dog and minimal benefit to the dog's tumor.
Well-nourished patients not only show better overall health, increased tolerance to veterinary interventions (such as surgery, radiotherapy or chemotherapy), and increased immune response.
The ideal anti-cancer diet for a dog is not yet known, although it is known to be the dog's nutrition, not cancer, should be the priority.
The diet should consist of a relatively small amount of simple carbohydrates, a modest amount of fats (especially omega 3 fatty acids) and an adequate amount of proteins with high bioavailability.
Numerous studies have shown that a high-fat, low-carbohydrate diet contributes to a greater likelihood of remission (when combined with chemotherapy) and longer survival times.
Since the metabolic changes that occur in a dog with cancer are permanent, even when the cancer goes into remission, feeding an adapted diet may be necessary for the rest of the dog's life.
What is included in the dog's anti-cancer diet?
First, a very important note: any changes in the diet should be consulted in advance with your dog's veterinarian.
It is wise to enlist the help of a veterinary nutritionist who will consider your dog's specific needs, especially if they are undergoing any additional treatment such as chemotherapy. Even supplementation is discouraged without the knowledge and consent of a specialist.
But if your doctor suggests that you try changing your diet by making homemade meals, here are some of the things that can be recommended:
All ingredients should be fresh, highly bioavailable, easily digestible and tasty, with a good taste and smell.
Many cancer patients lose their appetite due to treatment or disease, and yet these dogs must be willing to eat, eat a lot.
Veterinarians have various pharmacological appetite stimulants that may be helpful in maintaining the appetite of non-eating dogs. They are intended to prevent anorexia and weight loss.
If a dog with cancer stops eating, the doctor should consider enteral feeding - using a nasogastric tube (which passes through the nose and throat into the stomach) or a gastrostomy tube (which is surgically placed in the stomach).
Such measures, while they look quite dramatic to the owner, can be of great value to the patient and are generally short-lived.
Conventional veterinarians may disagree, but a holistic approach is becoming increasingly apparent among clinicians.
They recommend that caregivers use organic meat as part of their anti-cancer diet.
The last thing a cancer patient needs is to deal with pesticides, antibiotics, and extra bacteria that are usually found in non-organic meat.
In this situation, the body must focus on removing toxins as well as fighting cancer. Fresh, organic, high-quality meat is both appetizing and bioavailable.
Fish Oil Supplements
Rich in omega-3 fatty acids, which have been linked to inhibiting cancer and boosting the immune system.
Fish oil can be absorbed more easily by your dog's body than flaxseed oil, which is its close cousin.
Known and used for its oxidizing properties, this vitamin can be easily administered in the form of tablets.
Antioxidants neutralize free radicals as a natural byproduct of normal cellular processes.
In addition, antioxidants need to be replenished every time omega-3 supplements are administered.
Cruciferous vegetables like broccoli and dark green leafy vegetables like spinach are healthy for any dog, but especially for cancer patients.
In humans, diets high in cruciferous vegetables - such as broccoli, cauliflower, cabbage, and watercress - have been linked to a lower risk of lung, stomach, and colon cancer.
Especially broccoli is a source of bioactive compounds (indoles and isothiocyanates, including sulforaphane), which have strong anti-cancer properties.
In addition, the fiber provided by vegetables is essential for maintaining normal gut health, which in turn is crucial to your overall health.
Mashing vegetables and mixing them with food can improve palatability and increase acceptance of even more picky dogs.
Digestive enzymes are recommended to help support your dog's digestive function, especially when switching to a new diet.
Small amounts, such as a small clove daily, may be recommended.
Research provides convincing evidence that garlic and its sulfur components are effective inhibitors of the neoplastic process.
It is suggested to follow a diet with the following proportions:
- < 25% węglowodanów,
- 35-48% protein,
- 27-35% fat, with over 5% omega-3 fatty acids
- 2% arginine (dry weight).
Antioxidants such as vitamins E, C and A are anti-cancerous.
Selenium, vitamins A and K3, arginine, glutamine, and garlic have been shown to be beneficial in some experimental conditions. While this is promising, there is little evidence to support the specific uses of these nutrients.
To be clear: no veterinarian is going to suggest that a diet can cure cancer.
The dietary approach to angiosarcoma will not be curative, but there is a chance that the patient will endure the chemo more easily.
The goal of managing an anti-cancer diet should be to maintain overall health, weight and appetite, which in turn will greatly assist conventional veterinary treatment, all of which will ensure a good quality of life.
Spleen angiosarcoma in dogs - prognosis
A diagnosis of HSA always has a poor prognosis, the only exception being skin-derived hemangiosarcoma without internal involvement.
The statistics for the diagnosis of spleen hemangiosarcoma are quite disastrous.
It is a very aggressive tumor in dogs, with high mortality, a median survival of 3-6 months and a 10% annual survival rate.
Most of the primary tumors are in the spleen and many dogs experience tumor rupture and bleeding into the abdominal cavity.
By the time the dog handler brings the dog to the clinic, the tumor has metastasized in approximately 50% of patients.
It is estimated that more than 80% of affected pets have microscopic metastasis at the time of diagnosis. Therefore, even though surgery to the direct source of bleeding saves lives, it is generally not curative.
Chemotherapy can prolong survival, but usually only for a short time.
Even when the dog was diagnosed by accident, meaning the tumors were detected before they ruptured and bleed, the average survival time for surgery alone is around 6-8 months.
The most unlucky dogs have visible metastases at diagnosis. The survival times for these dogs can be in the order of a few short weeks.
It is estimated that 24-45% of dogs diagnosed with HSA will spread the disease to the right atrium of the heart.
The most problematic is that there is little information that can help determine whether the spleen mass is cancerous or not before a tissue biopsy is taken, so owners are forced to decide to undergo emergency surgery without having all the information they may need.
What factors influence the prognosis in dogs with HSA?
Procedure (splenectomy, chemotherapy)
Surgical removal of the spleen mass is the cornerstone of treatment for almost all dogs with spleen hemangiosarcoma.
Unfortunately, due to the aggressive biological nature of this tumor, the prognosis for dogs with HSA is poor even with surgery and supportive therapies.
In the case of surgical intervention alone, the median survival time (median survival time is defined as the period during which 50% of patients are still alive; however, this means that 50% of patients die within this time) varies between one and two months (some sources give that up to four months).
Survival times may vary depending on the stage of the tumor at the time of treatment.
Median survival time for dogs with spleen HSA undergoing surgery and chemotherapy is approximately 4-6 (up to 8, according to some sources) months.
Chemotherapy prolongs survival by several months. Unfortunately - there is no madness ?
Angiosarcoma cells inevitably develop resistance to chemotherapy, so only 10-15% of dogs diagnosed with spleen HSA will live a year or more after diagnosis.
Unfortunately, ultimately all dogs with HSA pass away due to metastasis or spread of the cancer to other organs, even though it is not evident at diagnosis.
Without surgery, the median survival time can be days or weeks and is very variable as decaying spleen tumors can rupture rapidly at any time and cause severe internal bleeding which, if left untreated, is often fatal.
If treatment is not possible, euthanasia should be considered to prevent suffering from internal bleeding.
Apart from local recurrence, the causes of death are multiple metastases, usually to the lungs, abdominal organs, heart and central nervous system.
The clinical advancement of the dog's tumor
The most important prognostic parameter in dogs with spleen HSA is the clinical stage of the tumor:
- Grade I - Tumor confined to the spleen.
- Stage II - Tumor limited to the spleen with rupture of the tumor / spleen or tumor of the spleen with involvement of regional lymph nodes.
- Grade III - Spleen tumor with rupture or involvement of regional lymph nodes and evidence of distant metastases.
Patients with a small, single tumor confined to the spleen and those who do not rupture the tumor and do not bleed into the abdominal cavity have a better prognosis.
Dogs with coexisting intra-abdominal haemorrhage at diagnosis have the worst prognosis. The median survival time for dogs with an unaccompanied tumor is 132 days (4.5 months).
The prognosis was more favorable for dogs with HSA in clinical advancement stage I and II - median survival time 4.5 months.
Prognosis better for HSA with mitotic index values below 11 - median survival time 9.5 months.
In the case of spleen HSA in animals, prognosis is not influenced by:
- histological subtype of angiosarcoma,
- the degree of histological malignancy,
- the presence of necrosis.
The location of the tumor
The prognosis of dogs diagnosed with hemangioma depends on the location of the tumor.
According to Professor Modiano, angiosarcomas that start or spread to internal organs, muscles or bone marrow are almost always fatal.
The main goal of treatment for these cancers is not necessarily a cure, but rather to slow or delay the spread of the disease, and to prevent or delay the onset of life-threatening bleeding episodes.
Therefore, surgery to remove the apparent tumor mass may be recommended in patients with stable HSA, even in the presence of extensive metastases.
Without treatment, most dogs diagnosed with internal organ hemangiosarcoma will die within one to two weeks, although some may survive for several months.
Anemia is a potentially life-threatening condition because it reduces the amount of oxygen delivered to the tissue.
Several studies have found that anemic dogs (HCT
It has also been reported that malignant spleen disease and the presence of bleeding into the peritoneal cavity are negatively associated with survival time. However, malignancy was not related to blood in the peritoneal cavity.
Indications for putting a dog to sleep with hemangiosarcoma
Spleen angiosarcoma is a very difficult disease for one more reason.
Affected dog owners are often forced to make important decisions using very limited data.
It is known that dogs with angiosarcoma have a poor prognosis as these tumors form from blood vessels and often spread to various organs throughout the body.
Many veterinarians give owners the option to choose euthanasia, especially when the dog is on the operating table and involvement of other internal organs is also apparent.
Most caregivers of sick dogs often find themselves confronted with options when making decisions.
They are aware that the chances of long-term survival are virtually non-existent, yet decide to seek treatment, saying the dog deserves a second chance, and if anything happens during or after surgery, they will be calm because they have made a decision for the welfare their pet.
What counts for them is the chance to spend a few more ordinary morning walks with their beloved dog.
This is so important that it justifies the risk of surgery and cancer diagnosis.
And of course there is always hope that the tumor will turn out to be benign.
For others, the important thing is that while treatment options exist, there is no cure for the disease.
They have carefully analyzed the statistics and do not want to give their dog any suffering.
Surgery can and is an effective option to remove the primary tumor and temporarily stop bleeding, but it cannot remove all of the metastatic disease that is already present at the microscopic level at the time of diagnosis.
Even after surgery and chemotherapy, disease will progress and cancer cells will continue to metastasize creating masses throughout the body.
Haemorrhage can occur from anywhere in the tumor and may cause temporary weakness. If the bleeding continues, the dog will show signs of shock and collapse.
To spare both the dog and the owner of the traumatic and painful experiences of this terrible disease, I always prefer to euthanize up to a week earlier than a day too late.
Regardless of how we deal with such a diagnosis, the priority should be the comfort of our ward.
This is about him.
Not for our conscience, mercy (sometimes misunderstood), peace of mind, or happiness.
Everything we do, any decisions we make at such moments should pass through the filters of our friend's comfort and quality of life.
I guarantee that if the matter is approached from the point of view of quality over quantity, everyone will benefit from it: the patient who will feel well throughout the treatment period, and his caregivers, who will be exposed to these last days, weeks or months with his beloved dog. what it means to enjoy a moment that lasts.
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