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  1. Animal Health Literacy

Be Smoke-free and Help Your Pets Live Longer, Healthier Lives

Why is smoking harmful?
What can smoking do to my pets?
What can smoking do to my dog?
What can smoking do to my cat?
What can smoking do to my pet bird?
What can smoking do to my guinea pig?
What can smoking do to my pet fish?
Nicotine Poisoning and Pets
Electronic Nicotine Delivery Systems
So, what can be done to help someone I care about cut back on or quit smoking?

Did you know that smoking is the leading preventable cause of death, disease, and disability in the United States?1 In the U.S., one out of every four non-smokers and two out of every five children are exposed to the harmful effects of secondhand and thirdhand smoke.2 That’s 58 million people exposed to something that’s preventable.3

Smoking’s not only harmful to people; it’s harmful to pets, too. If 58 million non-smoking adults and children are exposed to tobacco smoke, imagine how many pets are exposed.

Both secondhand smoke and thirdhand smoke hurt pets. Secondhand smoke is exhaled tobacco smoke and the smoke from the lit product itself. Thirdhand smoke is smoke residues that get on skin, clothes, furniture, carpets, and other things in the smoker’s environment, including their pets’ fur or feathers.

There is NO risk-free level of exposure to secondhand smoke.4

Why is smoking harmful?

Smoking can cause diseases of nearly all organs of your body. Adult smokers can become ill or die from smoking-related diseases like heart disease, chronic obstructive pulmonary disease, lung and bladder cancer, stroke, hardening of the arteries, and asthma.5 Adult non-smokers exposed to secondhand smoke can develop heart disease, stroke, and lung cancer. Secondhand smoke can also cause asthma, ear infections, and sudden infant death syndrome in children.6

Did you know that one cigarette can contain almost 600 ingredients? When burned, that same cigarette releases over 7000 chemicals.7 Ninety-three are on the FDA’s list of “Harmful and Potentially Harmful Constituents in Tobacco Products and Tobacco Smoke”. Some members of that club include:

  • Ammonia
  • Arsenic
  • Benzene
  • Carbon monoxide
  • Formaldehyde
  • Hydrogen cyanide
  • Lead
  • Mercury
  • Nicotine
  • Toluene
  • Uranium-238.8

Over time, smoke-related chemicals build up wherever a person smokes. That old “smoke smell” you notice when you enter a smoker’s house or car, or a hotel room where someone has previously smoked? That’s thirdhand smoke. It’s a residue made of tobacco smoke chemicals that remain from the smoke that filled the inside of the house, car, or hotel room. Some of those chemicals get re-released later, back into the air. Some stay around because they’re sticky, oily, or waxy.9 A good way to understand thirdhand smoke is to think of it as a toxic chemical layer cake:

  • it builds up in areas where people smoke
  • it can last for months even after a smoker has stopped smoking—like a “gift” that keeps on giving
  • it can be released back into the air as gases or ultra-fine particles after reacting with chemicals normally present in the air, like nitrous acid and ozone.10, 11

Nicotine, a major component of tobacco smoke, likes to stick to things such as furniture, fabric, walls, carpet, and clothing.12 It also likes to react with different chemicals present in the air, like nitrous acid. Everyday items like gas-burning stoves, automobiles, and tobacco smoke generate the pollutant, nitrous acid.13, 14 The reaction between nicotine and nitrous acid forms cancer-causing compounds. Some of these compounds like to stick to surfaces and household dust, while others go back into the air as gases.15 People and pets are exposed to the harmful compounds by breathing in the gases or ingesting or inhaling contaminated house dust. People are also exposed by touching coated surfaces and then accidentally transferring the cancer-causing compounds from their fingers to their mouths.16

Like children, dogs and cats spend most of their time on or near the floor, where tobacco smoke compounds concentrate in house dust, carpets, and rugs.17 Dogs, cats, and children can absorb these compounds through their skin and inhale them in contaminated house dust or as ultra-fine particles and gases that were released back into the air.18

Pets can also ingest tobacco smoke compounds by licking their owner’s hair, skin, and clothes. You can think of a pet owner who smokes as another “surface” that thirdhand smoke can stick to. Even if pet owners go outside to smoke, when they come back into the house, the thirdhand smoke comes with them.19

Because it’s so sticky, thirdhand smoke is also very stubborn to remove, if it’s removable at all.20 One study showed that even when smokers’ homes were cleaned and prepared for sale, thirdhand smoke was still present in the dust and on household surfaces months after someone had last smoked in the homes.21

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What can smoking do to my pets?

Scientists are investigating the effects of tobacco smoke on pets, but the amount of information available is small compared to the amount available about the effects of smoking in people. Still, the information we do have is important and sheds some light on what happens to pets exposed to secondhand and thirdhand smoke.

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What can smoking do to my dog?

For dogs that already have breathing or lung issues, inhaling tobacco smoke can worsen their symptoms and chronic coughing.22

Dogs can develop changes in their airways and lungs that are like those found in people who smoke. Ultra-fine smoke particles can activate the immune system of people. A type of white blood cell in the lungs involved in this immune response is called an alveolar macrophage.23 Alveolar macrophages watch what comes into the lungs, and if they detect something abnormal, they phagocytize or “eat” it to get rid of it.

Alveolar macrophages, special kind of cells normally found in the lungs, are the lungs’ front line against infections. They recognize invading bacteria, fungi, or viruses and send out help signals to other cells in the immune system telling them to join the fight.24 Alveolar macrophages also act as mini-housekeepers because they get rid of dead or dying tissue and other harmful things, like particles of tobacco smoke, dust, or plant pollen.25 When harmful things get into the lungs, more alveolar macrophages are recruited to roam around, look for, find, and get rid of them. People who smoke, therefore, have an increased number of alveolar macrophages because their bodies are trying to get rid of all the tobacco smoke particles in their lungs. Dogs exposed to tobacco smoke also have an increased number of alveolar macrophages—some of which contain black smoke particles—likely for the same reason.26

How tobacco smoke affects a dog depends on the length of the dog’s nose. Why? Because noses are big air filters. Have you ever dusted a dirty room and then had to blow your nose? Chances are you had black-looking yuck on your tissue afterward. The hair and mucus in your nose and the mucus in your sinuses act like glue traps. They trap particles like dust, pollen, and tobacco smoke, and keep them out of your lungs. Bigger noses, therefore, will trap more particles. This holds true, especially in dogs.

Long-nosed dog breeds like Greyhounds, Borzois, and Doberman Pinschers that are exposed to tobacco smoke have a doubled risk of nose cancer.27 Their noses filter out a lot of inhaled tobacco smoke particles, which stay trapped in their noses so less get into their lungs. Unfortunately, this puts the tissues inside the nose and sinuses in contact with a lot of toxic, cancer-causing particles, leading to the increased risk of nose cancer.

Short- and Medium-nosed breeds, like Pugs, Bulldogs, Beagles, and Brittany Spaniels, have a higher risk of lung cancer. Why? Because their noses are much shorter, fewer tobacco smoke particles get filtered out and more go directly into the lungs.28 Those ultra-fine particles like to go deep into the lungs, leading to the increased risk of lung cancer.

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What can smoking do to my cat?

Cats are careful groomers, which keeps them looking beautiful. But grooming can be a bad thing for cats living in a smoking household. Cats breathe in secondhand smoke directly, just like dogs. When cats groom themselves, though, they also ingest thirdhand smoke particles that fall onto their fur.29

Studies show that cats living in smoking households have a two- to four-times increased risk of an aggressive type of mouth cancer called oral squamous cell carcinoma. The cancer is often found under the base of the tongue, where the thirdhand smoke particles tend to collect after grooming (Figures 1 and 2). Of the cats that develop oral squamous cell carcinoma, less than 10% will survive 1 year after diagnosis, even if they’ve had chemotherapy, surgery, or radiation treatment.30

Microscopic view of cat oral squamous cell carcinoma tumor. Photo courtesy of Dr. Shelley Newman, University of Tennessee, Knoxville.

Figure 1: Microscopic view of cat oral squamous cell carcinoma tumor seen in Figure 2, below.

Cat tongue with squamous cell carcinoma. Photo courtesy of Dr. Shelley Newman, University of Tennessee, Knoxville

Figure 2: Tumor from Figure 1. Cat tongue with squamous cell carcinoma. Photos courtesy of Dr. Shelley Newman, University of Tennessee, Knoxville.

Cats that live with people who smoke more than one pack of cigarettes a day have three times the risk of developing lymphoma, a cancer of the body’s immune system similar to non-Hodgkin’s lymphoma in people.31 The typical survival time of a cat with lymphoma, even with chemotherapy or surgery, is six months.32

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What can smoking do to my pet bird?

Birds are very sensitive to air pollution, especially tobacco smoke. They can develop changes to their respiratory system similar to those seen in children exposed to tobacco smoke.33

Birds that live in a smoking household breathe in secondhand smoke. And, like cats, birds like to groom or “preen” themselves. When they do so, they ingest thirdhand smoke particles that have coated their feathers. Birds are also exposed to thirdhand smoke by perching on their owners’ clothes or hands and absorbing the harmful particles through their feet or by preening their owners’ hair and ingesting the particles.

Birds that live with smokers can develop:

  • irritated sinuses
  • pneumonia
  • allergies
  • lung cancer
  • feather plucking
  • eye problem
  • skin abnormalities
  • heart problems
  • fertility problems.34, 35, 36

Some of these conditions, like pneumonia, lung cancer, and heart problems, can cause death. Other conditions, like allergies and feather plucking, can be difficult to treat if the bird is not removed from the smoky environment.

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What can smoking do to my pet guinea pig?

“Pocket pets” aren’t immune to the effects of tobacco smoke. In one study, guinea pigs exposed to secondhand smoke for more than 6 months developed microscopic changes in their lungs similar to those seen in people who smoke.37 They also developed other problems like emphysema, a disease where the tiny air sacs in the lungs, the alveoli, get “stretched out” and don’t work properly; and pulmonary hypertension, high blood pressure in the blood vessels from the heart to the lungs, due to the vessels being too thick or not stretchy enough.38

In another study, guinea pigs exposed to chronic tobacco smoke had decreased weight gain due to toxic effects on their metabolism.39 The study authors noted that the guinea pigs’ did not gain weight starting 5 weeks after exposure to tobacco smoke. Microscopic lung changes, like those described above, also occurred, but happened after the guinea pigs’ weight gain began to decrease.

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What can smoking do to my pet fish?

Believe it or not, smoking harms pet fish. How’s that possible? Well, nicotine is toxic to fish. Both secondhand smoke and thirdhand smoke contain a lot of nicotine. Because nicotine dissolves easily in water, it can eventually end up in a fish tank’s water and poison the fish inside it. Fish exposed to toxic levels of nicotine can develop muscle spasms, rigid fins, and loss of color. They may also die.40

Just how toxic are nicotine and other chemicals in tobacco to fish? In a simple experiment, scientists put one smoked cigarette butt into water containing 2-week-old fathead minnows. Half the fish died within 96 hours--from one smoked cigarette butt.41

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Nicotine Poisoning and Pets

Nicotine poisoning is a serious concern for pets, not only when nicotine is inhaled, but also when it’s ingested. How could your pet ingest nicotine? There are several ways, including eating cigarette or cigar butts, drinking nicotine refill liquid, chewing on nicotine refill canisters for electronic nicotine delivery devices, or chewing on the devices themselves (more on electronic nicotine delivery systems later).

Nicotine can be toxic even at small doses. Fatal doses in dogs and cats have been reported at 20 to 100 milligrams (mg).42, 43 How much of a tobacco product would a dog or cat have to eat to reach a dose of 20 to 100 mg? One regular cigarette can contain 9 to 30 mg nicotine, while one cigar can contain 15 to 40 mg.44 A dog or a cat wouldn’t have to eat many cigarettes or cigars to get sick. Although seemingly harmless, cigarette butts left in ashtrays at home or tossed outside also pose a danger because they contain 5 to 7 mg of nicotine.45 Not only can dogs and cats get into ashtrays and eat cigarette butts, but pet birds allowed to roam indoors can, too.46

Signs of nicotine poisoning in pets include:

  • vomiting
  • unsteadiness
  • drooling
  • tiredness
  • fast heart rate
  • shaking
  • weakness
  • seizures
  • death.47

If your pet eats a cigarette, more than one cigarette butt, a cigar, chewing tobacco, a nicotine refill capsule, or liquid refilling solution, it’s an emergency! Get him or her to your veterinarian or to a veterinary emergency clinic as quickly as possible. There is no antidote for nicotine poisoning. Your veterinarian can give supportive care like intravenous fluids and anti-seizure medications that may help your pet survive until the nicotine leaves his or her system.

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Electronic Nicotine Delivery Systems

You may be using e-cigarettes, e-pipes, e-pens, e-hookahs, or e-cigars because you think these are safe products to use. These electronic nicotine delivery systems (ENDS), however, can still cause problems for you and your pets. Some studies have shown that the aerosol made by these devices may expose you and, therefore, your pets to higher-than-normal amounts of nicotine and other toxic chemicals, like formaldehyde.48

At first, under the Tobacco Control Act, FDA could only regulate cigarettes, cigarette tobacco, roll-your-own tobacco, and smokeless tobacco. But, on August 8, 2016, a new law took effect which gives the agency the authority to regulate all tobacco products, including ENDS. The FDA can now:

  • prohibit sale of tobacco products to children under 18 years of age,
  • review new tobacco products before they are marketed,
  • review tobacco advertisements,
  • evaluate ingredients in new tobacco products, and
  • better protect from, and educate people about, the dangers of using tobacco products.

ENDS use capsules that can contain nicotine. Some of these capsules can be re-filled using a special liquid. Sometimes, pets—mainly dogs—find the capsules and bite them or get into the liquid refilling solution.49 In a March 15, 2016, letter to the editor of the Journal of the American Veterinary Medical Association, the Texas Poison Center Network reported 11 cases of dogs being exposed to ENDS or refills.50 Remember, there is no antidote for nicotine poisoning. If your pet gets into an ENDS, nicotine capsule, or the liquid refilling solution, get him or her to the veterinarian or to a veterinary emergency clinic as quickly as possible.

ENDS-related fires and explosions are also a risk to people and pets. In 2016, the FDA Center for Tobacco Products reviewed and summarized reports from other U.S. government agencies, the news media, and scientific articles about ENDS-related fires and explosions, finding that some events have resulted in life-threatening injury, and permanent disfigurement or disability.51 Although there were no reports of pets being injured, the risk still exists. Pets that chew on the devices may potentially puncture the cartridges or batteries, or they may inadvertently turn on the devices. Always keep ENDS and all other tobacco products out of reach of children and pets.

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So, what can be done to help someone I care about cut back on or quit smoking?

Anyone who is a smoker will tell you that quitting smoking is tough. But there are many great reasons to quit smoking! You may already know that quitting benefits you and the people around you, but now you know your pets also benefit.

You can find good information and tools online to help you or a loved one quit smoking. Some federal resources include:

  • The National Cancer Institute and the CDC Smokefree.gov site, which offers cell phone apps to help you quit smoking, like Quit Guide, QuitSTART, and SmokefreeTXT.
  • The U.S. Centers for Disease Control and Prevention’s (CDC) “Tips from Former Smokers” webpage. You can also call the CDC to get help at: 1-800-QUIT-NOW (1-800-784-8669).

Other good sources of information and tools to help you quit smoking include:


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