Canine cancer is one of the most common causes of deaths in dogs, particularly in older dogs. It’s estimated that half of the dogs over 10 years of age will develop some form of cancer. This is thought to be the result of better care for dogs that prolongs their lives so that they are more susceptible to cancer because … they live longer. Dogs simply used to die at a much younger age.
What is Hemangiosarcoma?
Most people know that the word “sarcoma” is scary because it’s a diagnosis for cancer. Add the prefix “hemangio” in front of it, and what do you have? Hemangiosarcoma (or HSA) is an aggressive form of cancer that is a malignant cancer of the blood vessels. And if your dog has hemangiosarcoma, you will need to treat it quickly and aggressively.
It spontaneously arises in tissue where there are blood vessels. The tumors most often grow in the spleen, liver or heart, as well as other parts of the body, including the skin (cutaneous hemangiosarcomas). Dogs are more affected by HSAs than any other species of animal.
The exact cause of hemangiosarcoma is hard to determine but there are opinions that it’s tied to genetics and/or environmental factors.
In humans, certain chemicals such as vinyl chloride have been associated with the development of certain cancers. Hemangiosarcoma is rare in humans, consequently there isn’t much research about it or its causes.
How serious is hemangiosarcoma in dogs? Well, it depends on where they are found. If they’re on the surface of the skin (cutaneous), they’re considered to be curable and not so serious. Cutaneous HSAs are caused by repeated exposure to the sun, and dogs with short white fur are more susceptible to getting them. (Note, though, that cutaneous HSAs can spread to other areas if they’re not removed and HSA tumors metastasize quickly and can spread to the brain, other organs, skeletal muscle and bone.)
If the HSAs are found in the spleen, heart, liver or other internal organs, it is considered a very serious disease and a life-threatening situation. By the time the symptoms are apparent, they have already spread within the body, traveling across the blood vessels to other organs and body parts. Most often this condition is accompanied by disseminated intravascular coagulation (DIC); in English that’s blood clotting that occurs imperfectly inside the blood vessels.
Types of Hemangiosarcomas
- Subcutaneous (hypedermal) Hemangiosarcoma – Dark red blood growth below the skin.
- Visceral Hemangiosarcoma – spleen – Growth on/in the spleen.
- Visceral Hemangiosarcoma – heart – Growth inside the pericardium (sac that encloses the heart).
Dogs That Are More Susceptible to Hemangiosarcomas
The following factors and breeds tend to be more prone to getting hemangiosarcoma:
- Dogs that are 6 – 13 years of age (though it has been seen in dogs less than one year old).
- Mid-to-large size breeds, especially German Shepherds, Golden Retrievers, Labrador Retrievers, Boxers, Dobermans, and English Setters.
- For cutaneous HSAs, dogs like Pit Bulls, Greyhounds, Dalmatians, and Italian Greyhounds, that have short white hair and are exposed repeatedly to the sun.
What Causes Hemangiosarcoma?
Cutaneous HSAs in dogs are thought to be associated with exposure to the sun. But, for the HSAs that attack the liver, heart, spleen and other organs, some vets believe they might be linked to exposure to certain chemicals, or perhaps there is a genetic component as certain breeds seem to get them more often.
Hemangiosarcoma In Dogs Symptoms
Unfortunately, if your dog has a hemangiosarcoma, most often you won’t know it until the afflicted dog collapses. This is because the tumors are fed by blood vessels, filled with blood, and can rupture and hemorrhage suddenly. Here is a list of typical symptoms:
- If the HSA is located on the skin, muscles or bone, you may see a swelling beneath the skin.
- Signs of circulatory shock (pale or white gums, marked weakness or lethargy, rapid heart rate, rapid breathing)
- Abdominal swelling
- Lack of muscle coordination
- Partial paralysis
- Sudden collapse
- Profuse bleeding — internal or external
- Crying/whining from pain
Treatment of Hemangiosarcoma In Dogs
Your vet will give your dog a complete physical and conduct laboratory tests. S/he may also biopsy the mass via exploratory surgery to diagnose HSA.
Obviously, the right treatment protocol will depend on where the tumor is, what stage it is in, and how your dog is doing.
Most vets recommend complete surgical removals of the tumor(s) when the HSAs are on the skin. Surgery can also be effective if the tumors are located in one region of the body and haven’t metastasized. And chemotherapy will also be needed.
But if the hemangiosarcoma is found in the dog’s internal organs, he’ll have to undergo aggressive and extensive treatment. If he is been bleeding internally, he’ll need a blood transfusion to replace the lost blood.
If the HSA is in the spleen (the most common location), the organ can be removed to stop the bleeding. But there’s not a lot of good news – this type of HSA is not often cured, since even if you remove the tumor, the HSAs metastasize quickly and spread to other parts of the body. But it may be possible to delay the return of the tumors. And again, chemotherapy will likely be part of the treatment.
Many people whose dogs are diagnosed with hemangiosarcoma decide that the poor prognosis and difficult treatment protocol are too much to put their pets through, and they choose to euthanize as the most humane alternative.
If you notice masses under your dog’s skin and/or any of the above conditions are noted in your dog, get him/her to a veterinarian as quickly as possible. The earlier hemangiosarcomas are detected the better prognosis for your dog.