Second-hand smoke and your dog

In the past I have been asked on many occasions if I feel that second hand smoke in the home is bad for dogs. Just recently the subject came up again when I received an e-mail from a reader asking the same thing.

While I could offer a very long winded personal opinion on this topic, I have decided to provide the following article which I hope will answer the question to some degree.

This was printed in the May Dogs in Canada issue. A multi-published writer, Jeff Grognet, B.Sc. (Agr), runs a veterinary practice in Qualicum Beach B.C., along with his wife Louise Janes, D.V.M. He writes:

"Second-hand smoke, also called environmental tobacco smoke (ETS), is known to play a role in the development of cancer, lung disease and heart disease in people. Now evidence shows it is a health hazard to dogs as well.

"ETS is linked to canine nasal sinus (nose) cancer. Dogs in ETS households have a greater chance of developing this cancer than dogs that are not exposed to second-hand smoke.

"Long-nosed dogs such as Collies are at the highest risk for nasal cancer. Two hypotheses have been proposed for this. One is that their longer nasal passages contain more cells than those of short-nosed dogs, so have a greater opportunity to develop tumors.

"The other hypothesis is based on how smoke is inhaled. Cigarette smokers inhale through their mouths and the carcinogens in the smoke are deposited directly in the lungs, triggering lung cancer.

"On the other hand, bystanders inhale ETS through the nose, which filters cancer-causing chemicals. You can imagine that these nasal filters are effective in long-nosed dogs so the carcinogens become concentrated.

"In contrast, squat-nosed dogs have shorter nasal passages that are less efficient at removing carcinogens from the air. The result - short-nosed dogs have fewer nasal tumors but more lung tumors than their long-nosed counterparts.

"Researchers at the Western College of Veterinary Medicine in Saskatoon also delved into the question of whether cigarette smoke affects overall health. They performed physical exams, had owners fill out questionnaires, and performed a myriad of tests.

"What they found was that dogs from smoking households had more muscle on the left side of the heart, supposedly reflecting a heart that is working harder to pump blood. This, along with poor relaxation of the arteries, indicated the dogs had high blood pressure.

"Although the changes in the dogs' hearts did not seem to create signs of illness, the same heart changes in people often lead to significant cardiac disease. We don't know what the heart changes mean for the dogs' long-term health, so studies are ongoing.

"As we share more of our lives with our dogs, they are exposed to the same environmental hazards that we are. We know that second-hand smoke is bad for people. Now we know it's bad for our dogs."

I hope this sheds a little light on the subject.

* Pet Chat is a weekly question and answer column written by Greater Moncton SPCA Shelter Manager Nanette Pearl. Do you have a question about pets, the Moncton SPCA or anything else "pet" related? Send your questions by e-mail to nanette@monctonspca.org or visit the Moncton SPCA website at www.monctonspca.ca. The staff and volunteers of the SPCA remind readers to please spay and neuter their pets.