New Research Finds Cigarette Smoke Causes Cancer in Pets

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New Research Finds Cigarette Smoke Causes Cancer in Pets, Even on Clothing

The harmful effects of smoking on human health have long been established. Now, a new study indicates that exposure to cigarette smoke, even on clothing in a smoke-filled environment, can damage the health of dogs.

Led by Purdue University veterinarian Deborah Knapp, the study investigated the health and lifestyle factors of 120 Scottish Terriers over three years.

The results revealed that dogs exposed to cigarette smoke had six times the likelihood of developing bladder cancer compared to those not exposed.

The median exposure to smoke for dogs with cancer was 10 pack-years, while for healthy dogs, the median exposure was 1.5 pack-years. One pack-year is equivalent to smoking one pack of cigarettes daily for a year.

To determine if dogs had been exposed to smoke, Knapp’s research team relied on surveys filled out by dog owners and analyzed the dogs’ urine for traces of a nicotine metabolite called cotinine. Interestingly, some dogs showed cotinine in their urine even though their owners didn’t smoke, leading researchers to believe that dogs might ingest cotinine through sniffing or licking their owners’ clothing.

Knapp explained, “If someone goes to a smoky concert or party and then comes home, and their dog jumps up on their lap and snuggles with them, the dog is going to be exposed to particulate matter in the smoke through the person’s clothing.”

The researchers chose Scottish Terriers for the study because this breed has a 20% higher risk of bladder cancer compared to other breeds. This provided a baseline for the research group and a specific focus on cancer development.

“We know that the genetics of Scottish Terriers play a huge role in making them prone to cancer,” Knapp stated. “If we used mixed-breed dogs for this study, we would need hundreds or thousands of dogs to find the same risk, and that risk might be harder to detect because those dogs’ genes aren’t predisposed to bladder cancer. This study took into account the predisposition of the dogs to cancer, and the sixfold increase in cancer incidence due to smoking exceeded that ratio.”

The study also confirmed and accounted for previous research errors, including exposure to pesticides, flea treatments, and shampoos; recurrent urinary tract infections; and living within a mile of a swamp, all of which increase the risk of bladder cancer in Scottish Terriers. The swamp-related reasons may be linked to increased pesticide spraying in those areas.

Researchers say these findings help reveal the connection between carcinogens and cancer and may be applicable to humans. They refer to dogs as “sentinels of human environmental risk” because their shorter lifespan allows them to manifest the effects of stimuli and develop diseases faster than humans. While the study aims to protect furry friends from preventable risks, the researchers encourage pet owners to reduce their pets’ exposure to smoke.

Knapp concluded, “We hope the insight pet owners gain from this is that if they can reduce their pets’ exposure to smoke, it will help their pets’ health. We hope they quit smoking altogether, for their health and to continue being companions to their dogs, but any measures to keep smoke away from dogs will be beneficial.”

The study was published in the Journal of Veterinary Medicine.

New Research Finds Cigarette Smoke Causes Cancer in Pets, Even on Clothing