Secondhand smoke could cause significant damage to a pet’s health, including deadly diseases. Veterinarian Carolynn MacAllister explains (via Live Science), “Secondhand smoke has been related to oral cancer and lymphoma in cats, lung and nasal cancer in dogs, in addition to lung cancer in birds.”
One factor that plays a job in pets acquiring cancer from secondhand smoke is that animals don’t only breathe within the smoke. Smoke particles fall onto their fur, after which they lick themselves, ingesting the carcinogens.
Cats like to lick things (like your face), and people which might be exposed to secondhand smoke have 4 times the chance of developing oral squamous cell carcinoma, an aggressive mouth cancer (via PetFinder). Smoking also causes malignant lymphoma in cats (via American Journal of Epidemiology).
In line with the American Lung Association, dogs with long noses are twice as prone to develop nasal cancer than short-nosed dogs since smoke residue has more room during which to collect and cause problems.