It probably comes as no surprise to any of us, to learn that smoking near your pet is not a good idea. Passive smoking will have a variety of detrimental effects on your pet’s health; particularly of course, with regards to their respiratory system. With this risk, also comes an increased risk of cancers. Furthermore, there is also evidence to suggest that animals suffer more from the effects of passive smoking than humans.

In this article we will examine the conclusions that the studies looking into the effects of passive smoking for pets came to.

What is in cigarette or tobacco smoke?

The smoke from cigarettes can contain over 5,000 different chemicals. Nicotine is probably the most well-known; however, there are also traces of heavy metals (arsenic for example) and toxins such as carbon monoxide and ammonia. Radioactive particles may even be present. 

Many of these chemicals are harmful to both humans and pets. As we know, animals are exposed both directly to the noxious smoke that fills their air space, which is generally called second-hand smoke. But they can also be impacted by the build-up of smoke on furnishings, clothes, and even their own coats (sometimes known as “third-hand smoke”). Cats and dogs, therefore, can both be exposed to significant amounts of smoke by living in a smoking household.

Why are pets at greater risk from passive smoking? 

Animals may suffer from increased detrimental effects from smoke within the home, due to their behaviours. Carcinogenic (with the potential to cause cancer) particles from smoke, as mentioned above, will settle in various locations. Carpets, sofas and on floors for example. As places our pets frequently rest and spend most of their lives, the risk to their health increases.

Such chemical particles may also settle directly on an animal’s coats too. This will also increase the risk of ingestion, through the act of your pet grooming and then swallowing. Cats may therefore be at significantly increased risk from ingestion.

What problems can smoking cause in pets? 

Those potentially carcinogenic chemicals in smoke will damage cells all throughout your pet’s body. Such damaging changes may result in deterioration in important cellular structure and function. It can also mean that the cells become more susceptible to malignant (invasive and harmful) change. As a result, the pet’s risk of cancer is increased, as well as the risk from a range of other conditions


Cancers may particularly affect the respiratory tract, from the nose, through the throat, upper airways, and of course, down through into the lungs. With a reported 60% increased risk of developing lung cancer in dogs, this is a significant concern. 

In cats, a 2-3 fold increased risk for the malignant cancer lymphoma in particular has been noted. This risk is doubled, compared to a cat living in a non-smoking home.

Asthma and lung disease

Smoke may also trigger asthma in cats which may cause difficulty breathing and a chronic cough. It may also contribute to bronchitis in dogs. Fibrotic (brittle), and emphysema type, lung diseases will also be worsened by breathing in smoke-filled polluted air.

A link with passive smoking in pets and weight gain has also been reported.

Skin disease and allergies may also be worsened in pets living in smoking households and nicotine may have an effect on your pet’s neurological system. 

And for fish and birds?

Whilst it may seem odd to consider, any fish kept within a smoking household will also be subject to smoke exposure. Toxins in the smoke may dissolve into the water in fish tanks, affecting the fish. Additionally, birds caged indoors will of course also be subject to smoke exposure. With very delicate and sensitive respiratory tracts, smoke can be particularly harmful to them.

And other hazards…

May come from cigarettes and ashtrays that are left around the house. Young or inquisitive dogs may accidentally ingest them and thus be exposed to an intestinal source of many toxins and a risk of intestinal obstruction.

What about nicotine replacement and vapes?

It is worth remembering that pets are also sensitive to nicotine. If nicotine replacement products such as patches, gum, inhalers or e-cigarettes are used, you should always be very careful that they are kept out of your pets’ reach. The solutions in E-cigarettes are worthy of specific note, given they may contain severely high levels of nicotine, alongside enhanced flavourings and aroma’s that make them attractive to dogs.

Dangers of ingestion of E-liquids include oral trauma (by chewing on the plastic containers), nicotine toxicity and gastrointestinal obstruction. Nicotine toxicity can be especially brutal, resulting in paralysis of the breathing muscles, and potentially sudden death.

How can your pets avoid these risks?

The obvious solution; stop smoking! 

Perhaps easier said than done, but stopping will undoubtedly be the best way to support your pet’s continued health (as well as your own!) If this is not a viable option, then all attempts should be directed towards only smoking or vaping outside, away from the environment that your pet lives in.

Second, and third-hand smoke can cause a variety of health problems for people and animals. Don’t assume that your dog is indestructible or your cat can’t be harmed.

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