Whether or not you're a smoker, you've no doubt heard a lot about the dangers of secondhand smoke to the people around you. But one thing you may not often hear about is secondhand smoke and pets. Your pets not only share your home, they also share the air you breathe.
Dangers of Secondhand Smoke and Pets

Secondhand and thirdhand smoke are as dangerous to pets as they are to humans. Secondhand smoke is any smoke released into the air that gets inhaled by non-smokers. Thirdhand smoke, which is the smoke residue that attaches to skin, fur and other surfaces, can be just as problematic, especially for cats. A study published in the American Journal of Epidemiology links environmental tobacco smoke to oral cancer in cats, who lick the toxins contained in smoke residue off of the fur when grooming themselves. Cats exposed to secondhand smoke run a greater risk of developing malignant lymphoma. Actually, any exposure at all to secondhand smoke may make a cat two and a half times more likely to develop this type of cancer than cats in non-smoking households. That risk increases with prolonged exposure.
Dogs who breathe in secondhand smoke are more susceptible to certain types of cancers, including lung cancer and nose cancer. The type of cancer a dog is more likely to develop actually depends on the shape of his head. Dogs with long nasal passages are more likely to develop nose cancer, while dogs with short snouts are more likely to contract lung cancer. Secondhand smoke may cause respiratory illnesses in dogs, including chronic asthma and bronchitis. Vetstreet adds that dog skin conditions are exacerbated by exposure to second and thirdhand smoke.