We've compared the "burden" your lovable dog has on the environment to that of an SUV more than once to comedic effect in this space. The more realistic and serious question for your two- and four-legged family members, however, is what can you do to lessen Mr. Fido's cancer burden? Not as much as you'd assume, says Wall Street Journal writer Melinda Beck in her recent Health Journal column about dog breeds and their propensity for cancer.

It's a familiar subject for Beck. Her family recently lost their seven-year-old, golden retriever Cody, not a complete surprise because an amazing 60 percent -- more than double the average of any other breed -- die from cancer. And, if the variety of cancer a golden retriever has is hemangiosarcoma, the first sign (sudden death) may be the only one.

Perhaps, the key problem: Cancers usually crop up in dogs after their breeding years, which is why some non-profit groups like the Morris Animal Foundation are sponsoring research projects to identify specific genetic markers that can pinpoint signs of cancer long before any breeding. Still, whether pure-bred dogs are more prone to cancer than mixed breeds remains very much up in the air, although a few studies have given the latter a 10 percent lifespan bump.

The dog breeds with the highest probability of encountering cancer during their lifetimes: Boxer, Golden Retriever, Rottweiler and Bernese mountain dog (review the WSJ below for a fuller list of breeds).

The cancer risks are definitely real and not limited to dogs either. We lost our oldest boy cat, Mr. Fido, at age 12 nearly two summers ago, after an 18-month bout with fibrosarcoma, a condition in which cancerous tumors grow beyond control on patches of skin where a pet has been vaccinated.

Wall Street Journal: Health Journal May 4, 2010

New York Times: Well May 5, 2010