Put Pauline Machado
World No Tobacco Day, celebrated on May 31st, invites us to reflect on the harmful effects of smoking on health — not only for smokers, but also for those who live in the same environment, including pets.
Specifically, dogs and cats are exposed to cigarette smoke passively, constantly, and silently. Therefore, for them, who have a much more sensitive sense of smell and lungs than humans, cigarette smoke represents a greater and more dangerous health risk.
Therefore, in this interview, we spoke exclusively with the Veterinarian. Rosiane da Silva , specializing in clinical medicine for dogs and cats.
Among other guidelines, Dr. Rosiane tells us how cigarette smoke impacts the respiratory, immune, and even behavioral health of pets, in addition to discussing diseases associated with passive smoking, such as chronic bronchitis, allergies, recurrent infections, and even cancer.
The veterinarian also highlighted the warning signs, ways to protect animals, and the essential role of awareness in this care. After all, choosing to quit smoking can be an act of love and protection—not only for yourself, but for those who share your life, your sofa, and even your bed!
Enjoy your reading!
Pet Med – What are the main health risks that cigarettes pose to dogs and cats?
Rosiane da Silva – The main risks are related to exposure to a multitude of toxic substances present in smoke. For dogs and cats, this translates into irritation of the airways, lung damage, an increased risk of respiratory problems and, in the long term, the development of chronic diseases and even cancer; in other words, constant exposure compromises overall health and quality of life.
Pet Med – How does cigarette smoke reach pets, and why is it so harmful, even without direct contact?
Rosiane da Silva – Passive smoke: This is the smoke that the smoker exhales or that comes directly from the tip of a lit cigarette. It spreads into the environment and is inhaled by animals.
Residual contamination: This is the most insidious and often underestimated form. These are the toxic particles that settle on surfaces, such as fur, furniture, carpets, and curtains, even after the cigarette has been extinguished. Pets come into contact with these particles when lying down, playing, or, especially, when licking themselves during grooming. It is harmful even without direct contact because the toxins are released into the air and settle throughout the environment, becoming a constant source of contamination for the animal, which breathes the same air and is exposed to contaminated surfaces.
Pet Med – What diseases can be caused or aggravated by exposure to cigarette smoke in animals?
Rosiane da Silva – The most common diseases include:
Chronic respiratory diseases: bronchitis, asthma – especially in cats, and airway inflammation.
Recurrent respiratory infections: pneumonia, bacterial and viral infections due to weakened local defenses.
Dermatological and ocular problems such as eye and skin irritation.
Cardiovascular diseases, because in some cases there is a higher risk of heart problems.
Cancer, primarily lung and nasal cancer in dogs, especially long-nosed dogs, and lymphoma in cats.
Pet Med – Is there a difference in the impact of secondhand smoke between dogs and cats?
Rosiane da Silva – Yes, we can say that cats are generally more affected, especially in a residual way. Cats are much more meticulous in their hygiene, and when they lick themselves to clean, they ingest the toxic smoke particles that have settled on their fur. This makes them more susceptible to developing lymphoma, which is a type of white blood cell cancer, and mouth cancer, as well as respiratory problems such as feline asthma.
Dogs also suffer from respiratory and eye problems due to smoke inhalation. Interestingly, dolichocephalic dogs, such as Collies and Dachshunds, seem to have a higher risk of developing nasal cancer, while short-nosed dogs, brachycephalic dogs, tend to have more lung and bronchial problems. The way air is filtered and where particles settle varies according to the anatomy of the snout.
Pet Med – Can exposure to smoke affect an animal's immune system or increase its vulnerability to infections?
Rosiane da Silva – Yes, exposure to smoke can indeed affect an animal's immune system. The toxins present in smoke irritate and damage the cells lining the respiratory tract, which are the first line of defense against microorganisms. This compromises the body's ability to remove particles and fight infections. Furthermore, the chronic inflammation generated by smoke can overwhelm the immune system, making the animal more vulnerable to bacterial, viral, and fungal infections, and hindering recovery from illness.
Pet Med – What are the clinical signs that may indicate a dog or cat is suffering from the effects of cigarette smoke?
Rosiane da Silva – The signs are varied and, initially, can be confused with other respiratory conditions. Some of the most common include:
- Chronic or frequent cough, especially a "dry" or irritating cough.
- Persistent sneezing.
- Difficulty breathing, such as gasping, rapid breathing, or labored breathing.
- Nasal or eye discharge, irritated or red eyes.
- Dull coat with a persistent cigarette odor.
- Lethargy, decreased energy, or lack of interest in playing.
- Loss of appetite or weight loss, in more advanced cases, and wheezing, especially in cats with asthma.
Pet Med – Are brachycephalic breeds, puppies, and animals with chronic respiratory diseases at higher risk?
Rosiane da Silva – Absolutely. Brachycephalic breeds, with short snouts, such as Pugs, Bulldogs, Shih Tzus, and Persian cats, etc., already have a naturally compromised respiratory anatomy. Their nostrils are narrower, their soft palate is elongated, and their airways are tighter. Cigarette smoke further aggravates this pre-existing condition, causing greater inflammation and respiratory distress, and can lead to more severe crises.
Puppies have respiratory and immune systems that are still developing, so early exposure to toxins can cause permanent damage to their lungs and immune system, making them more susceptible to infections and chronic problems throughout their lives.
Animals with chronic respiratory diseases, that is, those that already suffer from asthma, chronic bronchitis, or other respiratory conditions, have their symptoms intensified by smoke. The irritation aggravates existing inflammation and can trigger severe crises, requiring veterinary intervention.
Pet Med – Besides inhalation, can nicotine or toxic cigarette residue be absorbed through the skin, fur, or licking?
Rosiane da Silva – Yes, and this is a very important route of exposure, especially through licking. The residual form deposits toxic particles on all surfaces, including the animals' fur. When pets lick themselves to clean themselves, they end up ingesting these harmful substances. Nicotine and other residues are then absorbed by the gastrointestinal tract. To a lesser extent, absorption through the skin can also occur if there is prolonged contact or in large quantities, but the oral route (licking) is the most relevant.
Pet Med – And what about the real risk of cancer in pets associated with environments containing cigarette smoke?
Rosiane da Silva – Yes, the risk of cancer in pets associated with environments containing cigarette smoke is real and proven. The chemical substances present in tobacco smoke are carcinogenic, meaning they are capable of causing mutations in cells that can lead to the development of tumors.
In dogs, there is an increased risk of nasal cancer (especially in dolichocephalic breeds, where particles settle and irritate the nasal mucosa) and lung cancer.
In cats, there is a strong association between exposure to smoke and the development of lymphoma – a cancer of the lymphatic system – and oral cancer. This is due to the ingestion of toxins when they groom themselves, which irritate the mucous membranes of the digestive tract.
Chronic exposure to these carcinogenic agents leads to the formation of tumors over time.
Pet Med – Does smoking in another room or near a window eliminate the risk to animals?
Rosiane da Silva – No, it doesn't eliminate the risk. While it may reduce the immediate concentration of inhaled smoke, it's not an effective solution. Smoke doesn't respect walls or open windows. Toxic particles spread through the air and can enter other rooms. Even with the window open, some of the smoke is sucked back inside or settles on surfaces in the room.
Toxic residue on surfaces will still be a problem, as toxins settle everywhere, regardless of where the cigarette was lit. The only truly safe environment is one where there is no cigarette smoke at any time.
Pet Med – What practical steps can smoking family members take to protect their pet from cigarette smoke?
Rosiane da Silva – The most effective measure is to quit smoking completely. However, if this is not immediately possible, some actions can help minimize exposure, but never eliminate, your pet's exposure to cigarette smoke, such as:
- Smoking exclusively outdoors, away from animals and the home: This is the only way to avoid direct exposure to smoke.
- Change your clothes and wash your hands after smoking and before interacting with your pet. This reduces the transfer of germs.
- Do not smoke inside the car if your pet is present.
- Clean the environment frequently and thoroughly, including curtains, carpets, blankets, and wipe surfaces down often to remove any accumulated toxic particles.
- Avoid leaving ashtrays exposed. Ashtrays should always be clean and out of reach of animals, as ingesting cigarette butts and ashes is highly toxic.
Pet Med – Finally, give us a summary of how, in general, cigarette smoke impacts the quality of life and health of dogs and cats.
Rosiane da Silva – In general, cigarette smoke negatively impacts the quality of life and health of dogs and cats. It subjects them to chronic stress on their respiratory and immune systems, making them more prone to illnesses, infections, and, in more serious cases, the development of cancer. Pets end up having less energy and vitality, become ill or have respiratory difficulties, don't play, don't exercise, and don't interact as they should. Inflammation and respiratory diseases can cause constant coughing, shortness of breath, discomfort, and pain. Animals chronically exposed to smoke tend to live shorter lives and with a lower quality of life. In short, exposure to smoke transforms the home into an environment of continuous risk to the pet's health, compromising their physical and emotional well-being.
In this respect, I would also like to reinforce the idea that the responsibility for the pet's health rests entirely with its owners. Often, the relationship between the owner's smoking and the animal's health is not immediately obvious to people, and the symptoms may be attributed to other causes. It is essential that veterinarians educate family members about the risks of passive smoking, as awareness is the first and most important prevention tool.
Another important point is that there is no "safe" level of exposure to cigarette smoke. Even occasional exposure or small amounts can have cumulative and harmful effects. Animals, because they live in the same environment as their owners and have more sensitive respiratory systems, are true "sentinels" of domestic air quality. What is harmful to us is often even more harmful to them.
Finally, it's crucial to remember that animal welfare goes beyond food and access to basic veterinary care; it encompasses a safe and healthy environment. Protecting pets from cigarette smoke is an act of love and responsibility that directly impacts their quality of life and longevity. Encouraging smoking cessation among pet owners is not just a matter of human health, but also of animal public health.
