Hemangiosarcoma: Canine Cancer
Hemangiosarcoma, or hemangio for short, is not just a hard-to-spell or pronounced word; it's a deadly and common cancer in our beloved dogs.
We are 10 years into the Morris Animal Foundation's Golden Retriever Lifetime Study. They have found that 75% of the dogs that have died so far died of cancer, and almost 70% of those cancers were some form of hemangiosarcoma.
This killer is not exclusive to Goldens. It is also common in German Shepards and Portuguese Water Dogs. This disease can take any breed and has also been found in wolves and coyotes.
The largest risk factor seems to be age, as hemangiosarcoma is more prevalent in middle-aged and older animals. Although larger breeds appear more at risk, small breeds also succumb.
Hemangiosarcoma Is a Blood Cancer
Overall, hemangiosarcoma is responsible for 5-7% of canine cancers. It is a blood cancer. More specifically, hemangiosarcoma is a cancer of the cells of blood vessels. These veins and arteries form the highway throughout the body through which blood travels.
Typically tumors form in the spleen, liver, skin, or heart. The blood vessels in the tumor are called tortuous, which means they are not straight and smooth but somewhat bent, crooked, and bulging. This allows blood to pool instead of flowing smoothly through. Pooled blood clots and clots block blood flow. When this happens, tumor cells die, which initially seems like a good thing. However, in this case, it causes ruptures in the tumor that leak blood (internal bleeding).
Minor ruptures may not cause any change in your dog's behavior. Therefore, this cancer often grows undetected until a massive rupture leads to severe internal bleeding. The dog (and you and your veterinarian) are then fighting for his life. Without emergency surgery, good timing, and a fair portion of luck, many dogs don't make it past this point, leaving stunned and grief-stricken owners wondering what happened. How could he have been fine this morning and gone this afternoon?
I Have Lost 3 Goldens to This Hideous Killer
My very first Golden, Keely, was 8 years young. She had been playing with our other dog and suddenly wouldn't move. Her gums were white. An emergency ultrasound found a slight bleed on her spleen. We assumed it was from getting T-boned by the larger dog. She was observed for a time. When the bleeding stopped, we thought we were out of the woods. We should have done surgery, but back then, we didn't know what we know now. A week later, she was gone.
Years later, I returned from work and couldn't get in the door. Chauncy was flat on the ground right in front of it and wasn't getting up. Frantic, I managed to get in through a different door and called my dear friend and neighbor, a veterinarian. There was nothing we could do but say goodbye. His spleen had ruptured, and his belly was full of blood. It was too late. He had been fine that morning.
Leo was my heart dog, that rare soul you feel has been connected to yours throughout eternity. We were too late to save him too. When we found the tumor, his platelets, the cells that make blood clot, were so low we couldn't do surgery. We tried to boost the platelets and go in a few days later. His spleen was massive with a giant tumor that had obviously been leaking and was at risk of bursting. We couldn't save him. I tortured myself for a long time, feeling that he would have been fine if I had just taken his spleen out earlier. Since dogs can live without a spleen, for a time, people were doing just that hoping to prevent this cancer. But research on this disease has shown that removing the spleen does not help.
New Research Findings
Recently some promising research has been released by the Morris Animal Foundation and AKC's Canine Health Foundation.
Hemangio does not seem to originate in the spleen, liver, heart, skin, or other sites where it is commonly found. These may be secondary locations where this cancer landed and grew. So removing organs to prevent it, such as taking out the spleen, won't stop it. It will then land in a different organ. Instead, hemangio seems to arise from blood-forming cells, which are primarily in the bone marrow in mammals.
Researchers have also found 3 different subtypes of Hemangio: angiogenic, inflammatory, and adipogenic.
These 3 subtypes can respond differently to chemotherapy which may be why dogs react differently to the treatment.
In addition, a cardiac medication, Propranolol, has been shown to have some effect in some cases.
Current research with the Shine On Study is looking into another treatment called eBAT. Hemangio cancer cells have been found to have 2 proteins on the surface targeted by eBAT to deliver a toxin specific to those proteins, creating a very inhospitable environment for the tumor.
These treatments could be a game changer for our precious pets. Currently, surgery and chemotherapy, if done in time, can add 5-7 months to their life. But 90% of dogs are gone within a year of diagnosis, and 100% are gone in 2 years.
Given the sneaky nature of the disease, earlier detection is needed, which is another focus of research.
The Shine On Study, dedicated to reducing the impact of hemangiosarcoma, developed a risk score by applying artificial intelligence to the results of blood tests to help identify dogs at risk for developing cancer.
Other researchers are working on additional methods to screen for cells in the bloodstream and genetic markers that would help us identify dogs at risk.
The Texas A&M Veterinary Medicine Department offers the Nu.Q cancer screening blood test. This test measures amounts of nucleosomes in the blood and is said to be 76% accurate at detecting systemic cancers in dogs (77% effective for lymphoma, 82% for hemangio, and 54% accurate for histolytic sarcoma). As nucleosomes are also released through massive inflammation in addition to cancer, this test may not be useful in dogs struggling with allergies which can also lead to systemic inflammation.
If you are interested in adding this profile to your pet's annual screening, discuss it with your vet and ask them to look into this test to see if it might be helpful for your pet.
Know Your Dog
I encourage you to get online and learn more about hemangio but, more importantly, know your dog.
Do you know what color your dog's gums usually are?
Would you be able to tell if they looked pale (a sign of anemia caused by bleeding)?
Knowing your pet's normals is the first step to recognizing something is abnormal.
Sudden collapse would undoubtedly send you to the ER. But how do we find this monster before we get to the point of massive internal bleeding?
Any changes in behavior should be watched and checked out by your veterinarian. Panting and drinking a lot after exercise is normal, but excessive panting and drinking water without exercise could indicate something problematic like a bladder infection — it was also reported by owners in the Golden Retriever Lifetime Study who lost their dogs to hemangio. So was intermittent lethargy or fatigue, which could indicate just about anything!
Early Detection Requires Advanced Diagnostic Testing
Abdominal ultrasounds look for signs of tumors in the liver, spleen, and other organs. You can easily add them to your dog's checkup. But how often should we do them? Although I have my older dog checked every 6 months, I know someone who did the same thing and suddenly lost her active agility champion just like everyone else, without warning or having seen anything on an ultrasound.
We need advanced diagnostic testing from researchers, scientists, and veterinarians, and they need us. While funds to support research are always welcome, consider participating in research. The Canine Health Information Center (CHIC) stores DNA samples from purebred dogs for research studies to pull from. Purebred dogs are needed as they have known pedigrees. Clinical trials are always ongoing. So if your dog does have a diagnosed disease of any kind, consider enrolling him in a trial or study. AKC's Canine Health Foundation has links to numerous studies around the country.
9 Tips to Reduce the Risk of Developing Hemangiosarcoma
Finally, take steps to reduce your dog's risk of developing hemangio and other forms of cancer (and yourself too):
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Get regular medical checkups with dental exams.
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Avoid exposure to secondhand tobacco smoke.
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Eliminate toxic chemicals in your dog's environment like weed killers and insect killers
Remember your dog is barefoot and can absorb chemicals off lawns through his paws or by licking them.
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Provide good quality nutrition and maintain a healthy weight — a higher quality food may not require as much feeding.
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Provide fresh water — water bowl slime is real and not healthy for your pet.
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Keep your 4-legged friend physically fit.
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Protect your dog's skin from the sun with adequate hair and avoid excess time in the sun. Dogs have thin skin, and UV rays can cause cancer in them, just like us.
Think shade and minimize the time in the sun between 10 a.m. and 3 p.m., just like us!
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Replace plastic bowls with stainless steel or ceramic.
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Don't let your pup drink from puddles that may harbor lawn chemicals and parasites.
Talk to your veterinarian about other ways to keep your pet healthy.
Here are some useful websites with research and information: