Hemangiosarcomas are a form of cancer which originates in the endothelium, which is the
lining of blood vessels and spleen. As might be expected of a tumor arising in the blood system they are highly malignant
and can be found almost anywhere in the body since blood vessels are necessary in almost all body tissues. There is a strong
predilection for the spleen, pericardium and heart. These tumors are most common in middle aged or older dogs which are medium
sized or larger but can occur in any breed. German shepherds are reported to be more susceptible to this tumor than most dog
breeds. In our practice golden retrievers also seem to have a higher than normal incidence.
these tumors arise in internal organs there is often little warning that they are present prior to time they cause severe
clinical signs of disease. A common estimate of the average time from discovery of the tumor until death occurs in affected
dogs is six to eight weeks but death occurs more rapidly than this in a number of cases.
of Hemangiosarcomas in Dogs
Visible bleeding, usually in the form of nosebleeds, and signs associated with blood
loss, such as tiring easily, episodes of unexplained weakness, pale color to the mucous membranes of the mouth and eyes, increased
respiratory rates, abdominal swelling and depression are the most common presenting signs for patients with hemangiosarcoma.
A few dogs just suddenly die with no clinical signs having been noted by their families prior to death. Bleeding disorders
associated with hemangiosarcoma are sometimes confused with immune mediated hemolytic anemia (IMHA) because the type of anemia
caused by the two conditions is very similar and early clinical signs are often very similar, as well. Hemangiosarcomas can
cause very large tumors, sometimes as large as ten or more pounds, when they affect the spleen.
most instances tumors of this size in this location are found on physical exam. In other cases the tumor affects the heart
and is hard to find on a physical exam and even easy to miss or X-rays. Sometimes there are hundreds of small tumors spread
throughout the body and surgical exploration or an autopsy are the only ways to identify the problem.
Intravascular Coagulation (DIC) Usually Accompanies Hemangiosarcoma
The blood disorder
that most commonly accompanies the presence of hemangiosarcoma tumors is disseminated intravascular coagulation (DIC). This
is blood clotting that is occurring inappropriately inside the blood vessels. It uses up all of the blood clotting elements
rapidly and dogs with this condition usually have platelet deficiencies, increased blood clotting times, decrease in fibrin
content in the blood and an increase in fibrin degradation products (FDPs). This is probably the cause of death in most dogs
affected with hemangiosarcoma.
Diagnosis of hemangiosarcoma can be accomplished in a number of
ways. Identification of a tumor in the spleen or heart raises a high degree of suspicion for this tumor. Abdominal swelling
is also highly suggestive in an older large breed dog. If fluid is aspirated from the abdomen and it looks like blood it is
even more suggestive of hemangiosarcoma. If blood is drawn and will not clot when left in the syringe it is another sign
that a dog may have this tumor. In some cases careful evaluation of the type of bleeding disorder present is necessary to
raise the suspicion of hemangiosarcoma.
Hemangiosarcoma Treatment in Dogs
If a tumor is identified when it is small it may be possible to remove the spleen if the tumor is there or even to remove
tumors found near the heart and prolong the pet's life. Most of the time this will not make much difference, though. These
are highly malignant tumors and most have spread by the time they can be identified. To the best of my knowledge there is
not a very successful hemotherapeutic or radiation protocol for this cancer at this time but dogs treated with chemotherapeutic
agents do live a little longer than dogs that do not receive this treatment.
Treatment for the
bleeding disorders and aggressive supportive care also prolong the life of patients with hemangiosarcoma. If treatment for
IMHA or immune mediated thrombocytopenia (ITP) are instituted due to confusion over the underlying cause of clinical signs
early in the diagnostic process there is not likely to be any harm to the dog.
Due to the tendency
to look for an inciting agent in IMHA and ITP it is a good idea to consider an autopsy exam if a dog dies before a definite
diagnosis of any of these conditions can be made. Finding hemangiosarcoma saves a lot of agonizing over possible causes of
the death of a friend. There are no known predisposing factors other than size and breed that I am aware of for hemangiosarcoma.
Osteosarcoma (and other types of bone cancer in Canines)
There are many different types of cancerous tumors that dogs can get; however, bone cancer can be one of the
more difficult to diagnose because the tumors don't show up as readily. There are many different types of bone cancer that
can develop in dogs. Some are more common than other, but here are the 6 most common forms of dog bone cancer.
1. Osteosarcoma Is the Most Common Bone Cancer.
often referred to as OSA, is the most common type of bone cancer that develops in dogs. OSA destroys a dog's bones from the
inside out. It can be very painful for you dog has the tumor continues to grow. OSA is most common in older, large breed
2. Chondrosarcoma, which is referred to as CSA, is the second
most common type of bone cancer that is found in dogs. CSA is a cancer of the cartilage and usually found in bones that are
flat like the skull or the ribs. This, on average, is not as malignant as OSA and can usually be treated by removing the tumor.
Many dogs get Chondrosarcoma Bone Cancer.
3. Fibrosarcoma is a fairly rare
form of bone cancer and is often called FSA. This cancer is typically treated through surgery on the infected area.
The surgery can involve amputation of the effected area. This bone cancer is usually found in the jaw, ribs and vertebrae.
4. Hemangiosarcoma Usually Affects Younger Dogs.
This is also a rare form of bone cancer that only impacts about 5% of dogs that have bone cancer. This form of cancer
usually effects younger dogs and is often treated with medication and amputation.
Osteochondrosarcoma is Very Rare.
This kind of tumor is very
rare and occurs in the lining of the bone, most often in the skull. Treatment options include surgery, but because of where
the tumors are often located, surgery can be difficult.
6. Primary Joint Tumors
This cancer is a little more common in dogs. A dog with this cancer will start to show symptoms that aren't all that
uncharacteristic of osteoporosis dogs get. The recommended treatment is amputation, but chemotherapy is an option you could
also discuss with your veterinarian.
While the bone tumor dogs get may vary in type, the most
common treatment is amputation. This may seem extreme, but if it can limit the effect of the tumor on your dog it may be worth
it. The treatment decision will be a discussion that you and your veterinarian will need to have.
Malignant Histiocytosis (a category of Dog Cancer Lumps)
Dogs develop many types of skin lumps, most of which aren't cause for concern, but a few are cancer lumps and
should be immediately evaluated by a veterinarian. Here are the following types, among which is malignant histiocytosis.Histiocytosis
There are three forms of histiocytosis, and
only one of them is malignant. However, all three look similar, forming large, hairless nodules, which usually have ulcers.
The malignant form affects both the skin and internal organs and has no known effective treatment.
Lymphoma is a common
dog cancer that can occur in the liver, spleen, lymph nodes and other organs. Those that occur in the lymph nodes are often
seen on the skin. However, you may be able to feel other internal lumps with regular inspections. Tumors may develop in the
lymph nodes and swell, but cause no other symptoms. Additional symptoms include itching, redness and ulcers around the tumor.
Treatment usually involves removal of the tumor, radiation treatment and/or chemotherapy, which can have varying degrees of
success. Treatment is usually less effective on lymphoma of the skin.
Two common types are fibrosarcoma and hemangiosarcoma. Both are associated with the skin and are very aggressive.
Since they may spread quickly, immediate action is required. Most veterinarians recommend removal, even if that means large
chunks of muscle and bone. Amputations may also be required.
usually associated with vaccinations or injections and forms at that site, most commonly in between the dog's shoulder bones,
where they receive most injections. These tumors form strange shapes and are very firm.
are usually caused by sun damage and may appear on the chest or abdomen. They often ulcerate and are usually dark in color.
Mast Cell Tumors
This is another common cancer that exhibits itself
in the form of tumors. In this case, one or more tumors may be present, varying in size and location. Some mast cell tumors
are very small and easily overlooked. They may appear smooth, bumpy or ulcerated and may be dark or discolored.
Mast cell tumors are usually grouped into grades, which vary from level 1 to 4. Level 1 are the most slow-growing
while level 4 are fast-growing and likely to metastasize. Treatment and prognosis vary largely on the grade of cancer and
the advancement of the tumor.
common type of tumor is squamous cell carcinoma, which is commonly associated with sun damage or chronic skin problems. These
tumors may appear one of two ways: cauliflower-shaped lesions that are commonly ulcerated and appear most commonly on the
lips and nose or larger, crusty ulcers that appear on the legs or other parts of the body where skin irritation may occur.
Treatment of these tumors may involve surgical removal or radiation, depending on the location.
Many types of tumors that appear on your dog's body can be cancerous or benign.
Basal cell tumors are an example of this. Though this type of tumors is a cause for concern, it may also be benign. Basal
cell tumors form into lumps, often around your dog's head, neck or chest. They may be fluid-filled, causing them to feel squishy,
or dark in color, but this is not always the case. Because these tumors don't often metastasize, they can usually be removed,
if cancerous, without requiring chemotherapy
Canine melanoma is a malignant tumor. A melanoma is manifested
through skin lesions that have unusual shapes or colors. Moles can turn into melanomas when they suddenly change shape and
color. A melanoma is made up of melanocytes, which are the cells that also determine the dark pigmentation of the skin. Canine
melanomas are typically located on the skin, toes, mouth or behind the eyes. Melanomas are more frequent in white coated dogs
and certain dog breeds. Cancer is a serious disease and should be detected as early as possible, so as to be able to stop
it from spreading and improve the life quality of the pet.
Symptoms of Canine Melanoma
Melanoma in dogs may pass unnoticed due to the coat, which covers the skin and the location of the lesions.
The most visible signs of melanoma are on the skin in the form of lesions that are dark in color and have irregular
shapes. Watch out for moles that change their size, color and shape and can turn into melanomas. These moles may be itchy
and can frequently bleed. Melanomas may also occur in the dog's mouth or on the toes. When the mouth is affected, there will
be other symptoms such as bad breath, excessive drooling, sneezing, coughing or trouble swallowing. This may also cause refusal
to eat and weight loss.
When the cancer is in metastasis, the dog will experience fatigue, nausea,
depression and behavioral changes.
Causes of Canine Melanoma
Melanomas in dogs don't have a clearly established cause, but may be linked to genetics and extended sun exposure,
especially in white coated dogs. Certain breeds are more susceptible to having melanomas. It is important to keep white coated
dogs away from sun and use suitable sun screen, to prevent the occurrence of melanomas.
Melanomas in dogs can be diagnosed through a medical examination. The
vet must establish how advanced the cancer is. Blood tests may reveal a low white blood cell count. X-rays are also performed
to establish if the cancer is in metastasis. The melanoma may also be checked, and in some cases a biopsy will be performed.
The treatment of canine melanoma should focus on removing
the melanoma or preventing the cancer from spreading. The vet will establish if surgery is possible or recommended. If surgery
is not possible, the vet will prescribe chemotherapy and radiation therapy.
However, even with
surgery or treatment, the cancer can still reoccur or spread further. The dog should be carefully monitored and any alarming
signs should be reported to the vet. A dog with melanoma can live a quality life, provided he gets the necessary care and
It is highly important that the dog is groomed on a regular basis, so that you detect
possible melanomas as early as possible. Check inside the mouth for dark spots or lesions and look at the toes as well. The
early detection of a melanoma can help the vet administer therapy and possibly prevent the cancer from spreading through the
rest of the body.