Can Secondhand Smoke Harm Your Pet?

In thDr. Jim Humphries, Founder of the Veterinary News Networke past 45 years, the number of smokers in the United States has decreased to less than 20% of the population and almost 70% of those current smokers want to kick the habit.  Could an understanding of how secondhand smoke affects our pets help encourage more people to quit?

By: Dr. Jim Humphries, Certified Veterinary Journalist, Veterinary News Network

The history of smoking tobacco may reach back many hundreds of years, but research in the 20th century has made it clear how harmful this habit is.  Furthermore, secondhand smoke has been implicated in the illnesses and even deaths of non-smokers.  What’s even more disturbing is that smokers may have unknowingly contributed to severe disease in dogs and cats.

Most people understand that secondhand smoke from cigarettes contains an incredible number of hazardous substances and many of them are carcinogenic.  These chemicals are found in high concentrations in carpets and on furniture around the home.  Pets sharing this environment will get these toxins on their fur and then ingest them during normal grooming.

Dr. Ann Hohenhaus, a board certified specialist in veterinary internal medicine and certified veterinary journalist, has written that increased numbers of smokers and smoking in households corresponds with higher levels of the by-products of nicotine metabolism in pets sharing that home.  She further describes how carbon deposits are often seen in the lungs of these animals.

Research is now showing that our pets’ health is affected in ways similar to what is seen in humans.

X-ray of dog with lung cancerIn the early 1990s, researchers found correlations between nasal cancers in dogs and the presence of smokers in the home.  There is also a concern that environmental tobacco smoke may increase the incidence of lung cancer in our canine friends as well.

Cats may actually be at higher risk for serious disease when they live in a smoking environment.  As mentioned above, many cigarette smoke toxins settle to low levels in the home and cats will pick up these substances on their fur.  Because of their fastidious grooming habits, cats end up ingesting a higher level of chemicals and this leads to a greater chance of several types of cancer.

Lymphoma is a cancer of white blood cells and is one of the most common cancers seen in our pet cats.  When smokers are present in the cat’s household, the risk for this killer is increased by two or three times over cats living in non-smoking homes.  Sadly, when our feline friends are diagnosed with lymphoma, the prognosis is very poor and many won’t survive another six months.

Another serious cancer with links to secondhand smoke is a cancer of the mouth known as squamous cell carcinoma, or SCC.   Studies have linked a higher risk for SCC in cats living in smoking homes.  Again, the prognosis is very grave and most pets won’t survive another year.

An unpublished study has also found that the levels of nicotine found in the hair of dogs exposed to second hand smoke is similar to levels found in children living with parents who smoke.

With more than 46 million smokers in North America and about 60% of the population owning dogs or cats, the risk for the animals is substantial.  Pets are often good at hiding signs of illness, so many smoking owners fail to realize the damage that their habit is causing to the four legged family member.

Of course, the best course of action is to give up the tobacco habit entirely.  It’s not only best for the health of the smoker, it will also greatly reduce risks for pets.  Understanding that it’s not easy to quit this addictive habit, people who smoke and have pets should attempt to minimize their pets’ exposure by smoking outdoors.

Lit cigaretteAnother important thing to remember is that smoking in the car with pets can create a toxic environment, even with the windows open.  Some states and Canadian provinces even ban smoking in cars when children are passengers because of the chance for serious exposures.  If you must smoke when you drive, leave your pets and kids at home!

Pets who are developing illnesses from secondhand smoke may exhibit symptoms ranging from lethargy to coughing to the appearance of masses in the mouth.  It’s important to have your pet seen by a veterinarian if any of these signs are noted.  To keep up to date with accurate animal health news, visit or

Dogs in the News – Dog Rescued from Frozen River Bites Anchor Woman during TV Interview


Max, a large Dogo Argentino was chasing a coyote across the icy Smith Reservoir in Lakewood, Colorado on  Tuesday, when he fell into the water. A West Metro firefighter, donning a wetsuit, braved the chilly waters and pulled the dog to safety. The rescue was captured by the SKYFox helicopters.  Max and the fireman were being interviewed by KUSA anchor Kyle Dyer on Thursday, when Max suddenly bit her on her face as she leaned in. Prior to this point, Max had been friendly. Kyle was taken to the hospital and has undergone reconstructive surgery on her face.

This tragic incident does bring home the warning that any animal can bite at any time. Max did give a warning snarl before the bite but there was little time for the anchor woman to react. Even professionals that work around animals on a daily basis can still be caught off guard and receive the painful bite from a dog or cat. There are certain signals that dogs do display before a bite and there are ways to approach dogs to avoid a confrontation. All parents should teach their children dog bite safety. A previous post on avoiding dog bites will help you to understand how to avoid dog bites.

Max was being evaluated at the Denver Animal Shelter where he will be quarantined for 10 days to ensure he does not have rabies, the shelter’s director said.

“Kyle is concerned about the viewers who may have been watching the interview and wants everyone to know she is okay.”

Let this be a lesson to all of us to be more careful around dogs, especially dogs you do not know well and are in unfamiliar settings.