I practice veterinary medicine and surgery in a sunny area. For those of you with a loved dog who gets a lot of sun, you may have wondered about the effects of sun on canine cancer.
As with many topics in medicine, there are a couple different things that have to be considered, as it is not a “good” or “bad” issue. Some sunlight daily seems to lower the overall rate of cancer. I will post on this next time. Let’s look at the “bad” side of sunlight in dog cancer today.
Many know about malignant melanomas in people, which occur more frequently in humans with fair complexion and sunlight exposure. Good news for dog lovers: dogs in the sun are at no increased risk for melanoma!
However, there are two cancers that do show higher rates in dogs that are outside a lot. The most common is hemangiosarcoma of the skin. More rare is the squamous cell carcinoma of the skin. Here’s an abstract.
Let’s look at hemangiosarcomas since they are common.
There are breeds that seem to have a higher risk for skin hemangiosarcomas. According to Veterinary Clinics of North America (2003), skin hemangiosarcomas are more common in poorly pigmented breeds and dogs with light hair, including Beagles, Bloodhounds, white English Bulldogs, English Pointers, Salukis, Dalmatians, and Whippets.
I personally see a lot of Greyhounds and American Staffordshire Terriers with skin hemangiosarcomas who have gotten a lot of sun too.
For more helpful tools and information to help your dog with cancer, get a copy of this informative guide
So if a dog is genetically prone to skin hemangiosarcoma, and also stays outside a lot, that’s two strikes. I don’t like two strikes. The more strikes you have, the higher the odds of bad things happening.
What do they look like? Hemangiosarcomas of the skin usually occur on the skin on the underside of the dog, including the belly, groin area, armpit, and inside of the back legs. A common appearance is a dark, firm mass, sometimes deep purple to black, emerging from the skin. Remember though that one can not differentiate a malignant tumor from a benign one without testing.
Bottom line: I would try to avoid keeping these dogs as outdoor pets. Additionally, sunscreen can help on areas where there is no hair for these breeds, if they are going out in the sun for extended periods.
Best to all
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.