This article is from the WSSF 2016 AFRMA Rat & Mouse Tales news-magazine.

By Chloe Bloom

Smoking is the biggest public health issue that the world has ever known. There are over 1 billion smokers in the world right now. The detrimental health effects on the individual smoker have been well known for decades.

We eventually discovered the dangers of passive smoking. These days without a second thought we protect our children and loved ones from the dangers of second hand smoke. As a society we find it totally unacceptable to harm children via passive smoking.

Our pets are often considered part of the family, they are almost like our children. However, all over the world they are being exposed to the dangers of second hand smoke. The carcinogenic chemicals that are present in cigarette smoke do not just affect humans. They are equally as damaging to animals. Many people are simply unaware of this and several awareness campaigns are trying to highlight this often unknown issue.

A small (but growing) amount of studies have already been conducted into the effects of passive smoking on animals. Researchers conducted a study on felines, tracking the rates of cancer in cats that live with smokers and comparing them to cats that do not live with smokers.

The study provided some shocking results. Cats who lived in a smoking household for one year were twice as likely to contract cancerous lymphoma in their lifetime. The longer the cat was exposed to the second hand smoke the higher their risk became. After living in a smoking household for over 5 years a cat is three times more likely to contract lymphoma than a cat that lives in a non smoking household.^[1]

It’s not just felines either. Studies have been conducted on all kinds of popular pet species.

Researchers exposed mice to second hand smoke for 6 hours a day over 5 days and then waited 4 months before dissection. They found that Tumor incidence was significantly greater in mice exposed to smoke (83.3%) than in controls kept in air (37.5%).^[2]

A study done by researchers at Colorado state university studied the effects of second hand smoke on canines. Similar to the experiment done on felines, they compared a group of dogs that had lived with smokers to a group that had not.

They found the dogs that lived with smokers had a much higher rate of respiratory illnesses such as asthma and bronchitis. They also found that nasal cancer rates of long nosed dogs increased by 250%. Suggesting that long nosed dogs trap the carcinogenic particulate in their nasal cavities, while short nosed breeds inhale the particulate directly into the lungs.^[3]

A study was conducted on pregnant rats^[4]. After conception the does were exposed to second hand smoke on a daily basis for 3 weeks. The does that were exposed to second hand smoke gave birth to much smaller and lighter rats than those in the non smoking control group. The infant mortality rate was also much higher with a 11.9% mortality rate for the rats exposed to second hand smoke, compared to a 2.8% mortality rate for the rats that were in the non-smoking control group.

Have you ever heard of third hand smoke? Third hand smoke is essentially the toxic residue that is left behind in your home when the cigarette smoke has disappeared.^[5] It gets everywhere, it gets on the floor, it gets in food and water bowls, and it gets on fur.

It is mainly harmful when ingested, which means adults are not massively at risk from it. But our pets (and small children) explore their world through their mouths. When an animal that lives in a smoking household eats or grooms themselves, they are ingesting this toxic residue with possible long term lethal consequences.

All these additional risks that our pets are exposed to are through no fault of their own. The only thing that makes them more likely to get these lethal and painful diseases is the fact they are owned by a smoker that smokes indoors.

So what can a responsible smoking pet owner do to reduce the amount of risk their pets are exposed to?

It goes without saying that quitting smoking is the best thing anyone can do for both the heath of themselves and their pets. This is the only way to totally reduce risk.

However, the most beneficial thing a current smoker can do (aside from quitting) is to smoke outside, all the time. Tricks like opening a window, smoking when pets are not around, or smoking in a separate room have been proven to be ineffective at stopping the spread of third hand smoke^[6]. There is simply no way for a smoker to smoke inside a home without harming the animals that live there.

Pets are part of the family. They deserve to be protected like our children. Please protect them from passive smoking too.

• Awareness campaign
• Third hand smoke Berkeley Lab News Center

1. Environmental tobacco smoke and risk of malignant lymphoma in pet cats. Bertone ER, Snyder LA, Moore AS. Am J Epidemiol. 2002 Aug 1;156(3):268–73.
2. 3. Studies of Cancer in Experimental Animals WHO IARC, 2004, 3:1 1323–1324
3. Cancer of the nasal cavity and paranasal sinuses and exposure to environmental tobacco smoke in pet dogs. Reif JS, Bruns C, Lower KS. Am J Epidemiol. 1998 Mar 1;147(5):488–92
4. Effects of Second-Hand Smoke and Gender on Infarct Size of Young Rats Exposed In Utero and in the Neonatal to Adolescent Period Zhu B, Sun Y, Sudhir K, et al. J Am Coll Cardiol. 1997;30(7):1878–1885. doi:10.1016/S0735-1097(97)00364-1
5. Formation of carcinogens indoors by surface-mediated reactions of nicotine with nitrous acid, leading to potential thirdhand smoke hazards Mohamad Sleiman, Lara A. Gundel, James F. Pankow, Peyton Jacob III, Brett C. Singer, and Hugo Destaillats, Proceedings of the National Academy of Sciences [Epub ahead of print], February 8, 2010.
6. Beliefs About the Health Effects of Thirdhand Smoke and Home Smoking Bans Winickoff JP, Friebely J, Tanski SE, et al. Pediatrics. 2009;123(1):e74–e79. doi:10.1542/peds.2008-2184.

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