Secondhand Smoke Pets Australia: 5 Alarming Risks to Dogs and Cats

By Michael Whelehan | Certified Master Hypnotherapist and Master NLP Practitioner | Breathe Hypnotherapy | Updated September 2026

Secondhand smoke pets breathe in every day is a risk many owners never think about. The reference text Tobacco in Australia, published by Cancer Council Victoria, lists lung cancer and cancers of the nasal cavity and sinuses in dogs, and lymphoma in cats, among the conditions linked to secondhand smoke exposure.

How Big Is the Secondhand Smoke Pets Risk?

The honest answer is that research on pets is smaller and less consistent than research on people. A 2026 scoping review of 11 studies on cancers, respiratory disease, and heart disease in dogs and cats found that over half reported statistically significant associations with secondhand smoke. The authors note some inconsistencies, but conclude the available evidence supports harmful effects. They also found tobacco biomarkers in pets’ blood, urine, and fur, confirming that pets absorb what is in the air of the home.

The RSPCA Australia is direct on one point: there is no risk-free level of passive smoke exposure for animals or people.

5 Risks for Secondhand Smoke Pets

• Dogs face airway cancers. Tobacco in Australia links secondhand smoke to lung cancer and cancers of the nasal cavity and sinuses in dogs. The scoping review also points to a possible link between muzzle shape and where cancers develop.
• Cats face lymphoma and airway illness. The RSPCA says cats exposed to secondhand smoke have a greater risk of lymphoma, a serious cancer, and of airway illnesses that can be life threatening. The scoping review reports that the risk rises with how long a cat is exposed.
• Cats also swallow smoke residue. According to the RSPCA, cats can ingest toxic residues from smoke when they groom their fur. The US FDA notes that tobacco compounds settle into carpets, dust, and surfaces where pets spend their time.
• Dogs may age faster and develop allergies. The RSPCA links secondhand smoke exposure in dogs to allergies, eye problems, and airway problems, and says there is evidence that it accelerates ageing. Tobacco in Australia describes the evidence for eye, respiratory, and skin disease as limited.
• Small pets are affected too. The RSPCA lists dogs, cats, birds, mice, guinea pigs, and fish as susceptible to the damaging effects of secondhand smoke.

How This Differs From Secondhand Smoke and Children

We have covered the human side of this in our guide to secondhand smoke and children. This article focuses on animals, whose bodies, habits, and living spaces mean they are exposed differently.

What Changes for Secondhand Smoke Pets When You Quit

When you stop smoking, the source of the exposure is gone. That is the clearest benefit the evidence supports. The studies above do not tell us how quickly a pet’s health improves once exposure ends, so this article makes no promise about that. Residue on furniture and carpets may take time to clear, so it is worth asking your vet what else to do around the home.

Smoking outside the house may reduce some exposure, but given the RSPCA’s position that no level is risk-free, quitting is the only option that removes it. No eligible studies looked at e-cigarette aerosol in pets, so its effect on them is unknown.

Why Willpower Alone Often Isn’t Enough

Most smokers already know the risks, and many love their pets deeply. Anyone who has tried patches, gum, or sheer willpower and gone back to smoking knows that caring about the consequences and being free of the habit are different things. Nicotine dependence runs through the subconscious mind and the body’s stress response, not just conscious decision-making, which is why so many quit attempts fail even when someone genuinely wants to stop.

How Hypnotherapy Supports Quitting

Hypnotherapy at Breathe Hypnotherapy works with the subconscious patterns that keep the habit running on autopilot. Michael Whelehan works with clients Australia-wide in a single Zoom session, and you can read more about how the process works.

To be clear, hypnotherapy does not treat any medical condition in people or animals. It helps people stop smoking by working with habit and trigger patterns.

Important Disclaimer

Breathe Hypnotherapy does not provide veterinary or medical advice and does not diagnose or treat any condition in people or animals. This article is general information about secondhand smoke and pets, based on Australian reference sources and peer-reviewed research, and it does not predict any individual animal’s health. Hypnotherapy at Breathe supports people to stop smoking or vaping. If your pet has a persistent cough, breathing difficulty, or any change in health or behaviour, contact your vet.

Ready to Quit For Good

If you’re ready to stop smoking or vaping, Breathe Hypnotherapy offers a free 40-minute assessment to check that it’s the right fit, then a single Zoom session, Australia-wide. If you quit and cravings return later, the lifetime relapse guarantee entitles you to a free re-session. Book your assessment with Michael today.