Secondhand Smoke and Pets

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Secondhand Smoke Harms Pets

  • In the U.S., almost twice as many households have pets than have children under age 18.1
  • About one-fifth of pet owners are cigarette smokers.2
  • Because pets, like small children, spend time near the floor where smoke residue concentrates, they may be at high risk of exposure to secondhand and thirdhand smoke.2,3
  • Thirdhand smoke is residue that lingers after the smoke is gone and can be found on clothing, sofas, and carpeting.3

Secondhand Smoke Hurts Dogs

  • Exposure to cigarette smoke may lead to asthma symptoms, lung cancer and other forms of cancer in dogs.4
  • Cotinine, a by-product of nicotine, has been found in the urine of dogs exposed to secondhand smoke in the home; dogs in non-smoking homes showed no cotinine.4
  • Dogs in homes of smokers were more likely to have difficulty breathing and more likely to develop lung diseases than those in nonsmoking homes.4
  • Long-nosed dog breeds have an increased risk for nasal cancer because the smoke stays in the nose longer. Short-nosed dog breeds have an increased risk for lung cancer because the smoke is not filtered in the nose and it goes directly into the lungs.5
  • The animal’s size also impacts health risks. Smaller dogs spend more time in intimate contact with their owners and are closer to cigarette smoke.4

Secondhand Smoke Puts Cats at Risk

  • Secondhand smoke increases the risk that cats will develop lymphoma, a cancer of the immune system.6
  • Cats that have live in a household with a smoker have a 2-fold increase in risk of oral cancer.6 Cats whose owners reported smoking 1-19 cigarettes per day had a significant (4-fold) increase in the risk of oral cancer compared to cats in nonsmoking households.6
  • While grooming, cats consume the cancer-causing chemicals that accumulate on their fur. The constant grooming exposes the mucous membranes in the throat to cancer-causing chemicals.7


  1. Hovell, M.F., & Irvin, V. L. , The public health significance of ETS exposure of dogs and other pets Nicotine & Tobacco Research, 2007. 9(11): p. 2.
  2. Milberger, S.M., Davis, R. M., & Holm, A. L., Pet owners' attitudes and behaviours related to smoking and second-hand smoke: A pilot study. . Tobacco Control, 2009. 18(2): p. 2.
  3. Matt, G.E., Quintana, P. J., Hovell, M. F., Bernert, J. T., Song, S., Novianti, N., Juarez, T., Floro, J., Gehrman, C., Garcia, M., & Larson, S. , Households contaminated by environmental tobacco smoke: Sources of infant exposures. Tobacco Control, 2004. 13(29): p. 8.
  4. Roza, M.R., Viegas, C. A.,, The dog as a passive smoker: Effects of exposure to environmental cigarette smoke on domestic dogs. Nicotine & Tobacco Research, 2007. 9(11): p. 5.
  5. Reif, J.S., Bruns, C., & Lower, K. S. , Cancer of the nasal cavity and paranasal sinuses and exposure to environmental tobacco smoke in pet dogs. American Journal of Epidemiology, 1998. 147(5): p. 4.
  6. Bertone, E.R., Snyder, L. A., & Moore, A. S. , Environmental tobacco smoke and risk of malignant lymphoma in pet cats. . American Journal of Epidemiology, 2002. 156: p. 5.
  7. Snyder, L.A., et al., p53 expression and environmental tobacco smoke exposure in feline oral squamous cell carcinoma. Vet Pathol, 2004. 41(3): p. 209-14.