Today it’s common knowledge that second-hand smoke causes cancer, but humans aren’t the only ones at risk. Researchers at Tufts University and Amherst College in Massachusetts have established that cats living with smokers are at increased risk for developing oral and intestinal cancer.
Know the Risks
The number of years, proximity and number of family members who smoke cigarettes all affect a cat’s chance of developing cancer. For example, cats with five or more years of exposure to one smoker have a 5 times greater risk for oral squamous cell carcinoma (SCC) than unexposed cats. If cats are exposed for less than three years, the risk is 3.3 times greater for developing oral cancer. Oral cancer is the fourth most common feline tumor. Sadly, most cats with oral cancer have less than a 10 percent survival rate at one year.
In addition, cats living with one smoker are almost twice as likely to develop intestinal lymphoma as their unexposed counterparts. With two smokers in the house, the risk of developing intestinal lymphoma doubles, making the cat about 4 times more likely to develop intestinal cancer than unexposed cats. Not to mention, lymphoma is the most common type of cancer found in cats.
Dangerous When Swallowed
Pollutants from tobacco smoke can settle on a cat’s coat and the residue is picked up by the cat’s tongue and ingested during grooming. These microscopic toxic pollutants pass into the esophagus, stomach and intestines, contaminating the entire intestinal tract.
The lymphocytes, part of the immune system, undergo mutation and cause lymphoma or cancer of the lymph glands. Researchers previously believed that all cats with lymphoma were infected with the Feline Leukemia Virus (FeLV). However, most cats in the past decade diagnosed with intestinal lymphoma tested negative for FeLV. Exposure to second-hand smoke, not a virus, is now viewed as a contributing causative factor to intestinal lymphoma.
Cats that develop lymphoma have a typical history of weight loss, soft stool, diarrhea or vomiting. Any one of these symptoms warrants a complete veterinary work-up to rule out lymphoma. On examination, the veterinarian may palpate abnormally thickened intestines, enlarged lymph nodes in the abdominal cavity or a mass or obstruction along an intestine.