04/19/2026
Cats are uniquely vulnerable due to their grooming behavior. To***co smoke particles accumulate on their fur and are subsequently ingested, resulting in repeated oral and systemic exposure over time.
Higher risk has been observed in cats living in smoking households, particularly those exposed for five or more years or in homes with multiple smokers, compared to cats in non-smoking environments. Cats whose owners smoked 1–19 ci******es per day demonstrated a significant fourfold increase in the risk of oral squamous cell carcinoma.
The risk is not limited to oral tumors. Cats exposed to household to***co smoke have a 2.4-fold increased risk of malignant lymphoma (95% confidence interval: 1.2–4.5), rising to 3.2-fold after five or more years of exposure (95% confidence interval: 1.5–6.9). Notably, risk increases in a dose- and duration-dependent manner.
Beyond carcinogenesis, to***co smoke exposure disrupts the balance between oxidants and antioxidants in cats. Significant increases have been reported in total oxidant levels, oxidative stress index, lipid hydroperoxides, protein carbonyls, and advanced oxidative protein products, alongside decreased total antioxidant capacity and reduced antioxidant enzyme activity.
In parallel, exposed cats exhibit elevated pro-inflammatory signaling molecules, including interferon gamma, interleukin-1 beta, interleukin-2, and interleukin-6, indicating activation of systemic inflammatory pathways.
Bertone ER, Snyder LA, Moore AS. 2003. Environmental and lifestyle risk factors for oral SCC in cats. J Vet Intern Med.
Bertone ER, Snyder LA, Moore AS. 2002. Environmental to***co smoke and lymphoma risk in cats. Am J Epidemiol.
Köseoğlu E, Yıldırım F, et al. 2023. To***co smoke induces oxidative stress in cats. Vet Res Forum.
