Saturday, March 29, 2014

Are You Overlooking This Major Potential Cause of Dog Cancer?

People often ask me what kinds of vitamins, supplements, vaccine abstentions or foods will save their dog from cancer. It’s an expected concern, since cancer is the primary disease-related cause of death in dogs. I have watched as health-conscious clients have blamed themselves when their dog is diagnosed with cancer, often believing they (or their vet) must have exposed their dog to carcinogens. 

Despite what marketing forces out there are saying (buy this wonder supplement! buy this natural pet food! Buy this well-bred purebred dog!), in my experience, many if not most canine cancers are facilitated hugely by genetics. We should not make the mistake of assuming that dogs are at highest risk from the poor nutrition/carcinogenic exposure/stress/lack of exercise combination that causes so much human illness.  These factors should not be ignored, but none of them, in my professional experience, tends to be the biggest problem for dogs. Rather, the primary issue is that they tend to be much more genetically vulnerable than humans. Unlike most cats or people, most dogs were deliberately inbred, or their recent ancestors were, so their risk of having genetic cancer is much greater.  It’s important to make this distinction.

So before you become preoccupied wondering if your purebred dog’s toys, rabies vaccine or dog bed might cause cancer, it’s helpful to first learn about the cancer statistics for its particular breed.  As just one example, according to the Morris Animal Foundation, 60% of Golden Retrievers die of cancer.  Sixty percent. They’re strongly genetically predisposed to lymphoma and hemangiosarcoma, as all vets know.

Similarly, a single type of aggressive cancer (disseminated histiocytic sarcoma) accounts for up to 25% of all deaths in Bernese Mountain Dogs, a canine whose average lifespan is a mere 7 years.  Great Danes, Greyhounds and Rottweilers are strongly predisposed to osteosarcoma (bone cancer). Boxers and English bulldogs are strongly predisposed to mast cell tumors. Schnauzers are at increased risk for cutaneous melanoma. The list goes on and on.

So if you ‘d do anything to avoid experiencing a cancer diagnosis in a canine companion, you might be asking yourself - should I purchase any purebred dog? It’s your choice if you wish to do so. However, before you do, it’s important to know that the dog breeding world is frequently unconcerned with the long-term health of dogs. Its actions are often shortsighted and its claims  deceptive.  In my experience, regardless of what many dog breeders (or their websites) claim, they often know only whether a puppy has the looks to sell, and little else.  I would not be the first veterinarian to share that the majority of my purebred patients have been  1.) genetically afflicted or at-risk at some stage in their lives and 2.) purchased by people who believed their dog had exceptional breeding that made the latter unlikely. 

If you do choose to go the route of buying from a breeder, please:

Know there’s a good chance you’re not getting what you think you’re getting.

Resist the urge to blame your veterinarian if a purebred dog of any kind is plagued by expensive, persistent or devastating genetic illness.  We cannot change genes. We can only manage the symptoms of those genes expressing themselves. Unfortunately, the diagnostics and treatments we need to do this are often costly beyond our control.

Resist the urge to insist that buying, branding and selling dogs is completely unrelated to pet overpopulation and shelter deaths. Dog breeding’s effect of creating “more dogs, less adopters” is frequently cited, but it requires more explanation:  if deliberately bred dogs or their potential lines of progeny don’t end up in shelters (which many do), most people breeding dogs still project the idea that their dogs are superior home companions. In actuality, many were instead “designed” to be either intense working dogs, or, on the other end of the spectrum, have been indiscriminately bred into health risk for the sake of “a look.”  One of these health risks is cancer. Unfortunately, breeding is now fueling the mindset that dogs are commercial objects before they are anything else. People from all walks of life and all levels of financial (in)ability are being “sold” on purebred dogs. Less adopters, indeed. More “objects” with overwhelming breed traits (including medical ones) being disposed of at shelters, indeed.

I know many wonderful people who show intense personal responsibility when it comes to their purebred dog--- they love it and would go to any lengths for it. They are model dog parents. But I try to encourage taking that devotion one step further; if we consider ourselves to be "dog lovers" concerned with the fate of dogs on the whole, buying and selling purebred dogs can be more medically and ethically consequential than we tend to assume.

So, are you someone who can’t stand the thought of having a dog go through genetic illness? Do you cringe at the thought of vet bills that amount to hundreds or thousands of dollars? Or can’t stand the thought of millions of healthy dogs being put to sleep in shelters annually? If so, when you’re thinking, “Should I buy this dog food?” or “Should I buy this supplement?” you might also want to consider, “Should I buy this purebred dog?”

When people ask me what kind of dog I recommend for being the most medically sound, I tell them, the more recent the purebred is in its lineage, the greater its predispositions to illness. Adopt a mix from a shelter or rescue - it will thank you, and you will thank me.