After reading my previous blog on melanoma, I had a client ask me, ‚ÄúAre there any cancers correlated with sun exposure that I should worry about?‚ÄĚ ¬†This prompted a discussion that quickly led to the topic of hemangiosarcoma, and I thought it best to use this discussion for my next blog. ¬†Reader be warned: this is a topic about a very aggressive and usually fatal cancer that has only limited response to available treatments. ¬†In other words, this is a less-than-sunny topic for discussion; but important nonetheless.

Hemangiosarcomas (HSA) are malignant tumors that grow from the cells that form the inner lining of our blood vessels. Theoretically, they can develop anywhere in the body, but in our canine companions there are three main areas that we see HSA: the skin, the spleen and the heart (we will talk about cats and HSA at the end of this blog). Let’s take a closer look at each of these areas.

The skin: HSA can develop on the external part of the skin and look like rosy red or black skin growths (usually on the non-haired or light hair colored parts of the skin). There has been an association between sun exposure and the skin form of HSA. Hemangiosarcoma can also develop just under the skin (we call this a subcutaneous mass) and can be felt as a nondescript mass. The skin form of HSA is considered the best form to have, as it is most likely to be completely excised (removed) with surgery. Subcutaneous HSA is more likely to have already spread to other tissues by the time it is found, so it carries a worse prognosis.

The spleen: By the time HSA is found in the spleen, it has likely already spread to other tissues. Sometimes it is found on a routine physical exam as your vet palpates your pet’s abdomen. Other times, it is found because your pet has had a recent history of lethargy, weight loss, inappetance, collapse, vomiting and/or diarrhea. As you can see, these clinical signs are quite vague and can be easily dismissed until they progress.

It's simple.We have the most comprehensive pet insurance for cats & dogs.

The heart: Oftentimes HSA is found in the heart because your pet suffers a severe cardiac collapse. This is often an emergency situation, and as you can imagine, carries a very poor prognosis.

Please understand, HSA has likely metastasized (spread from its initial location to other tissues) by the time it is found and diagnosed. This makes the treatment even more complicated. If your vet suspects HSA, don’t be surprised if they want to do bloodwork, take chest radiographs, perform an abdominal ultrasound and/or send the skin/subcutaneous tissues to the lab for histopathology. All of these tests can help your vet understand how progressed the disease is at the time of diagnosis, and thereby help you understand the best course of action for your four legged family member and yourself.

Surgery, chemotherapy and supportive care are all options for a pet diagnosed with HSA. Depending on the location, the amount of metastasis, and your pet’s current health status, your vet will have the best recommendations as to your options. Most dogs diagnosed with HSA (unless it is localized to the external skin), will succumb to the disease within weeks to months. Don’t be afraid to be honest with your vet about your wishes for your pet, and ask questions about your pet’s status. These will be difficult decisions to make, so try to understand your pet’s situation as best as you can so that you can make the best decision for you, your family and your four legged family member.

A note about HSA and cats: HSA can be seen in our feline friends, but it is not as common as it is seen in dogs. HSA is generally seen in the skin, internal organs, or oral tissues of our cats. Surgery and chemotherapy are the treatments of choice, but survival times with these therapies are not well understood. If your cat is diagnosed with HSA, your vet and/or veterinary oncologist is going to be your best source of information.

As you can see, the diagnosis of hemangiosarcoma is not one that vets or pet parents ever want to hear. Although the long term prognosis is not good, there are treatments and therapies that can help to make the short term more comfortable for your pet and allow you a little more quality time with your furry friend. And with Petplan pet insurance, paying for those treatments can be one less thing you and your family need to worry about while you take the best care of your pet.

Jul 17, 2013
Pet Health

Get covered with Petplan

An insurer who cares about your pets (nearly!) as much as you do.

Start quote

More from 

Pet Health


View All

Join Our Newsletter and Get the Latest
Posts to Your Inbox

By subscribing you agree to our terms and conditions.
No spam ever. Read our Privacy Policy
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.