Eighteen out of every 100 adults in the U.S. smokes. If anyone in your household is a smoker, so is your dog. And her risk for cancer is greater than for other dogs. Research at Tufts Cummings School of Veterinary Medicine has already shown that cats living in homes with smokers are at increased risk for lymphoma, and perhaps oral cancer, too. In fact, they are almost two and a half times as likely to develop lymphoma as cats in nonsmoking households. On that basis, it’s more than reasonable to assume that dogs who regularly inhale tobacco smoke are at a similar risk.
It may not just be the secondhand smoke — smoke your dog breathes in after you exhale — that causes a problem. There’s evidence that thirdhand smoke — tobacco toxin leftovers that stick on skin, hair, drapes, and upholstered furniture — can also make its way to your dog’s body and thereby predispose her to cancer.
Other environmental carcinogens to which your dog should not have to be exposed: lawn herbicides and insecticides. Transitional cell carcinoma of the bladder, a common tumor of the canine bladder that’s difficult to treat, has been linked to insecticide and herbicide exposure. Don’t allow your dog on the lawn until you’re certain that the chemicals you have applied have been absorbed and won’t be able to affect her. Following application, a thorough lawn watering or a good rain are likely to significantly reduce the amount of toxins your dog is exposed to. It’s not clear whether the chemicals get into the body through ingestion (the dogs licks her paws after walking on the grass) or via absorption through the skin. Either way, don’t take any chances.