(Dr. Iulia Mihai, DVM) The risks to smokers and people who are repeatedly exposed to cigarette smoke are well known. However, it is less well known that cigarette smoke can also affect pets that live in environments where smoking is common. Even if your pet does not directly inhale cigarette smoke, the smoke residue left on their skin and fur can lead to health problems.

Symptoms caused by cigarette smoke include respiratory problems, vomiting, excessive salivation, diarrhea, skin and heart problems, and eye irritation.

Repeated exposure can lead to inflammation of the throat and bronchi, manifested by chronic coughing. Nicotine, the main toxic compound in tobacco, is dangerous even in small amounts; ingesting just a few cigarettes can cause severe poisoning or even death in small animals.

In this article, you will learn why pets are at risk of getting sick, what the clinical signs are, what you can do, and much more.

What Is Secondhand Smoke? 

Secondhand smoke is smoke inhaled involuntarily. When nonsmokers are exposed to secondhand smoke, it is called involuntary smoking or passive smoking. The same is true for pets. When nonsmokers and pets breathe in secondhand smoke, they inhale nicotine and toxic chemicals just as people who smoke do. The more secondhand smoke they breathe in, the higher the levels of these harmful chemicals in the bodies of nonsmokers or pets.

Why is secondhand smoke a problem? Secondhand smoke has the same harmful chemicals that people who smoke inhale. There is no safe level of exposure to secondhand smoke.

Why Pets Are at Risk Too?

Pets are at risk because they live in the same environment as smokers and involuntarily inhale cigarette smoke. They spend more time indoors, close to the ground, where toxic residues accumulate. In addition, by cleaning their fur, they can ingest the harmful substances that have been deposited, increasing the risk of illness.

Understanding Secondhand Smoke: More Than Just Tobacco

A cigarette contains nearly 600 ingredients (tobacco leaf, as well as various additives such as moisture-retaining compounds, flavors, preservatives, substances for better burning, etc.). When a cigarette is burned, it creates over 7,000 chemicals that are toxic to health. In addition, over 69 of these chemicals can lead to cancer. Common toxic chemicals in cigarette smoke include ammonia, benzene, lead, formaldehyde, and tar. These substances can seriously affect health, and pets with a lower body weight are much more vulnerable to their toxic effects. In homes where smoking is frequent, toxic particles are deposited on furniture, clothes, carpets, and even the fur and skin of pets, which means that the dangers persist long after the cigarette is put out.

How Secondhand Smoke Affects Different Types of Pets

Secondhand smoke does not affect all pets in the same way, but in different ways, depending on their species, size, or other physical characteristics.

Dogs with long muzzles are more prone to developing nasal cancer because cigarette smoke reaches deeper into the upper respiratory tract. Those with short muzzles, on the other hand, can develop lung cancer because the smoke reaches the lungs faster. In addition, prolonged exposure to secondhand smoke can lead to various respiratory and even cardiac problems.

Cats, because they groom themselves frequently, are more at risk of disease because they ingest toxic substances. Among the most common diseases are chronic respiratory problems, oral cancer, and lung cancer. Clinical signs can include chronic coughing, difficulty breathing, weight loss, and lethargy.

Birds generally have fragile and sensitive respiratory systems. Therefore, their exposure to even small amounts of smoke can cause breathing difficulties, lung diseases, or inflammation. Moreover, secondhand smoke in birds can lead to feather plucking, skin infections, feather loss, and self-mutilation.

Small animals (amphibians and rodents) and reptiles are also at risk because chemicals can accumulate in the spaces they live in. Among the most common conditions encountered are respiratory, skin, or eye problems.

In all cases, the effects of secondhand smoke are cumulative. Even occasional exposure can have serious long-term consequences. Creating a smoke-free environment is essential for the health and well-being of all pets.

Signs Your Pet May Be Affected by Secondhand Smoke

Animals exposed to secondhand smoke may show several visible signs of health problems. Here are the most common:

• Respiratory problems: coughing, difficulty breathing, wheezing, and panting.

• Digestive signs: excessive salivation, nausea, vomiting, and diarrhea.

• Skin problems: excessive scratching, irritation, and dryness.

• Eye problems: irritation, tearing, and redness.

In the long term, repeated exposure can lead to inflammation of the throat, trachea, and bronchi. It is important to observe these signs and consult a veterinarian if there are changes in the animal's behavior or physical condition.

Short-Term Effects: Coughing, Wheezing, and Irritation 

Short-term exposure to cigarette smoke in pets can cause coughing, breathing problems, and airway irritation in animals. In addition, red eyes, a runny nose, increased salivation, and general discomfort are symptoms that indicate that the body is reacting to inhaled toxins.

Long-Term Effects: Cancer, Heart Disease, and Organ Damage 

Prolonged exposure to cigarette smoke in pets can increase the risk of certain cancers, such as nasal, lung, and oral cancers. The toxins can also damage the heart, liver, and kidneys, causing chronic diseases that can shorten the life span and quality. Moreover, repeated inflammation of the respiratory tract and oxidative stress contribute to damage to internal organs, and the risk of severe heart and lung disease is much higher in pets living in environments where there is constant smoking.

Reproductive and Developmental Impacts in Pets 

Passive smoking can also affect animal reproduction and development, leading to fertility problems, risky pregnancies, and negative effects on the growth of puppies or kittens. In birds, it can lead to decreased fertility and egg hatchability.

When to See a Veterinarian 

If you notice signs that your pet has been exposed to secondhand smoke, consult your veterinarian. Watch for persistent coughing, wheezing, labored breathing, vomiting, diarrhea, lethargy, red and watery eyes, or skin problems. If clinical signs appear and do not improve within 48 hours, consult your veterinarian as soon as possible. Pets with pre-existing conditions, very young pets, or senior pets are more vulnerable and are at increased risk for developing severe long-term complications. 

How to Protect Your Pets from Secondhand Smoke 

Protecting pets from secondhand smoke is essential for their health and well-being. Here’s what you can do:

• Create a completely smoke-free environment – don’t smoke in your home or around your pets.

• Make sure your pets don’t have access to rooms where smoking is allowed if smoking is unavoidable.

• Clean your pet’s fur and paws frequently.

• Vacuum and clean surfaces, carpets, and furniture frequently to remove toxic residue.

• Ventilate your rooms frequently to reduce airborne particles, but keep in mind that chemicals can linger for a long time.

• Quit smoking or use outdoor areas away from your pets.

Bottom Line

Secondhand smoke poses a serious threat to the health of pets. Repeated exposure to cigarette smoke can lead to various health problems, including severe respiratory problems, heart disease, skin problems, eye problems, and even cancer. The effects can be both short-term and long-term. The age, breed, and size of the pet can influence the severity of the effects. Pets that spend a lot of time indoors are more vulnerable to toxins in smoke. In addition, chemicals can linger on their fur and skin, furniture, or clothing, increasing the risk of ingestion and illness.

It is important to be aware of these things and try to create a smoke-free environment. If you cannot quit smoking, strictly limiting exposure in the spaces where your pets live is the most effective method of protection. In addition, careful monitoring of symptoms and veterinary consultation can prevent serious complications.