A bird is exposed to secondhand smoke.

Secondhand Smoke and Pets

No matter what your stance is on tobacco products, you’re probably well aware of their risks. With 93 chemicals identified as harmful or potentially harmful in a single cigarette, smoking is regarded by the Food and Drug Administration (FDA) as at least potentially dangerous to nearly every part of the body. Smokers are at an increased risk of developing respiratory conditions like chronic obstructive pulmonary disease (COPD) and bronchitis, reducing their fertility, and suffering from heart disease. While lung cancer is the condition most commonly associated with smoking, the Centers for Disease Control and Prevention (CDC) notes that the habit can cause cancer from the mouth and throat to the colon.

It’s not just smokers who are regularly exposed to the harmful ingredients in tobacco products. 58 million people and an unknown number of cats, dogs, and other pets are forced to inhale and ingest environmental tobacco each year.

Environmental Tobacco Smoke: Secondhand and Thirdhand Exposure

When smokers puff on cigarettes, cigars, pipes, and other combustible tobacco products, they consume smoke “firsthand.” As they continue, they also expose themselves and anyone around them to secondhand smoke from their exhalations and the burnt end of their tobacco product. Regularly inhaling secondhand smoke is especially harmful to infants and children, elevating the risk of ear infections, asthma, and sudden infant death syndrome.

Both children and pets are especially vulnerable to another type of environmental tobacco: thirdhand smoke. If you’ve ever walked into a room that reeks of stale cigarettes despite a lack of visible clouds or tobacco products, you’ve experienced thirdhand smoke. Pets and kids in smoking households often come in closer and more regular contact with thirdhand smoke than adults because of their relative proximity to the floor. In addition to settling on carpets and spreading through household dust, thirdhand tobacco particles cling to furniture, walls, and even the clothes, hair, and skin of smokers. Nicotine from this lingering tobacco smoke and residue can mix with other chemicals in the air to produce additional cancer-causing compounds that will stick around as well.

Thirdhand tobacco is remarkably resilient. A 2011 study published in Tobacco Control found that this residue could remain present in airborne dust and across household surfaces even after intensive cleaning and numerous smoke-free months.

The CDC reminds smokers and non-smokers alike that environmental tobacco smoke should be considered a potential hazard to anyone who comes in contact with it. Even short periods of exposure to environmental smoke are considered risky. The organization reports that around two and a half million non-smokers have died from indirect tobacco inhalation and ingestion since 1964.

Secondhand Smoke and Pets

Smokers who light up with pets nearby are all but forcing them to inhale the dangerous chemicals included in tobacco products. Studies into tobacco’s effect on pets suggest that they suffer many of the same health consequences from repeated exposure that humans do.

Secondhand Smoke and Dogs

Tobacco smoke is known to affect the canine respiratory system in much the same way that it affects the human lungs and airways. When it is regularly exposed to secondhand smoke, a dog’s immune system begins to ramp up production of alveolar macrophages, a particular kind of white blood cell. The human immune system responds the same way in anticipation of future irritants like smoke.

The impact of regular tobacco exposure on a dog will largely depend on the shape of the dog’s nose and mouth. Long-snouted dogs like Greyhounds have a natural filtration system that stops a good deal of tobacco smoke from reaching their lungs. Unfortunately, trapping smoke and chemicals in the snout means that these types of breeds are especially likely to develop nasal cancer as a result of secondhand smoke exposure. For breeds without long noses (including brachycephalic dogs like Pugs and French Bulldogs), smoke is more likely to cause lung cancer than cancers of the face.

Secondhand Smoke and Cats

Smoke inhalation is similarly dangerous for felines, especially those who are already suffering from respiratory conditions. Studies have found that regular smoking can dramatically shorten a cat’s life. Cats who live with pack-a-day smokers are three times as likely to suffer from lymphoma. Even after successful surgeries or chemotherapy, cats with lymphoma are only expected to live about six months.

Secondhand Smoke and Birds

Pet birds absorb nicotine and other chemicals through their skin and feathers. This can elevate their risk of developing lung cancer and a range of other conditions if they are exposed to secondhand smoke on a regular basis. For example, birds who live with smokers are prone to developing allergies, pneumonia, and chronic sinus trouble.

Secondhand Smoke and Other Pets

A bowl or tank won’t protect your pet fish from the health effects of second and thirdhand tobacco smoke. Nicotine from the air can easily find its way into the water and poison the fish inside. Fish who survive poisoning from nicotine may experience symptoms like pigmentation loss, stiff fins, and muscle spasms.

Pet health experts have also determined that secondhand smoke can have an adverse effect for small pets like guinea pigs. One study found that six months of tobacco exposure caused guinea pigs’ lungs to change in many of the same ways that a human smoker’s would. These guinea pigs were also more likely to develop emphysema and suffer from both hypertension and high blood pressure than those who occupied a smoke-free environment.

Thirdhand Smoke and Pets

Smoke inhalation is just one source of potential health hazards for pets living with smokers. Dogs, cats, birds, and small pets are continually exposed to thirdhand tobacco throughout the day as they groom themselves and interact with their owners.

Cats and Thirdhand Smoke

Felines use a big chunk of their day for self-grooming. Sometimes as much as 50% of a cat’s waking hours are spent on personal hygiene. This potentially exposes smokers’ cats to an especially large quantity of thirdhand smoke throughout the day.

Studies show that cats in smoking households are two-to-four times more likely to develop oral squamous cell carcinoma than others. This especially aggressive mouth cancer begins at the base of the tongue and is believed to result from smoke particles that enter the mouth during grooming. The prognosis for cats who develop this cancer (even those who get treatment) is not good. Just 10% of cats live for a year or more with the disease.

Birds and Thirdhand Smoke

Birds are persnickety about personal hygiene too. As birds preen their feathers, they may continually ingest chemical particles that have settled on them. The problem is compounded when bird’s elect to preen their owners’ hair and clothes as well. Even perching on a surface can prove dangerous, since birds absorb substances (including toxic ones) through their feet.

Tobacco Ingestion and Pets

Dogs and other pets aren’t always picky about what they eat. This appetite can get the better of them if they make a meal of tobacco products. Just a single cigarette may be enough to cause nicotine toxicity in a small cat or dog. Even discarded cigarette butts in ashtrays can poison pets with their small doses of potent nicotine.

Signs of nicotine poisoning include:

Symptoms tend to evolve quickly, so time is of the essence if you believe your pet may be suffering from nicotine toxicity.

Though they’re famous for curiosity, cats aren’t usually as adventurous as dogs when it comes to food. It’s comparatively unlikely that a cat will ingest tobacco and fall ill. That being said, it’s always safest to ensure that cigarettes, cigars, loose tobacco, and other potentially poisonous products are never kept where cats can reach them.

Pets and E-Cigarettes

Though they’re often billed as a safe, smoke-free alternative to the real thing, doctors and veterinarians aren’t so sure that e-cigs solve any of their predecessors’ problems. The FDA suggests that vaporized tobacco may expose pets to especially high levels of nicotine and other toxic chemicals like formaldehyde. Pets’ sensitive respiratory tracts are vulnerable to absorbing these chemicals. Animals can also re-expose themselves to these “thirdhand vape” chemicals throughout the day as they groom, preen, and interact with owners.

Among the components of a typical vaporizer is a small cartridge filled with a highly-concentrated solution of liquid nicotine and other chemicals. Pets can become seriously ill if they ingest even a small amount. Nicotine toxicity from e-cigarette liquid will result in similar symptoms to poisoning from other tobacco products, but they may progress more quickly and prove more severe. Contact your veterinarian immediately if your pet has ingested liquid nicotine.

Whether vaporizers are part of a smoking cessation plan or a permanent replacement for leaf tobacco, pet owners are advised to keep electronic cigarette components safely away from pets. Learn more about protecting dogs and cats from accidental poisoning.

Help from the Experts

For additional information on the risks of firsthand, secondhand, and thirdhand smoke, as well as help with quitting, check out these resources from the CDC.