We know that secondhand smoke can pose a serious health risk to children and nonsmoking individuals in a household with a smoker, but did you know that smoking in your home and car can also be fatal to your indoor pets?  Of the 5,000 chemicals identified in tobacco smoke, public health authorities have classified between 45 and 70 of those chemicals (including carcinogens, irritants and other toxins) as potential origins of the harmful effects of tobacco use. According to the Centers for Disease Control and Prevention, more than 126 million Americans who don’t smoke are exposed to secondhand smoke in their homes, vehicles, workplaces, and public places. This exposure causes thousands of lung cancer and heart disease deaths among nonsmokers every year.  Now we can add pets to this sad set of statistics. Research in dogs, cats and birds have shown definitive effects of secondhand smoke, but any and all indoor pets are likely to be affected.


How are pets exposed?



  • By ingestion of cigarette or cigar butts which contain toxins.

  • By drinking water that contains cigar or cigarette butts (which can have high concentrations of nicotine).

  • By breathing secondhand smoke.

  • By ingestion of nicotine replacement gum and patches.

  • By grooming smoke and chemicals contained in secondhand smoke off of their fur (cats, especially) – causes the smoke to be eaten as well as breathed.


Health Effects:



  • Breathing problems in dogs and asthmatic-like symptoms in cats

  • Skin and respiratory allergies

  • Salivation

  • Diarrhea

  • Vomiting

  • Cardiac abnormalities

  • Respiratory difficulties and respiratory paralysis

  • Collapsing trachea in small breed dogs

  • Feline lymphoma in cats

  • Lung cancer in dogs

  • Nasal cancer in dogs

  • Death: from 1-5 cigarettes and from 1/3-1 cigar can be fatal if ingested.


Secondhand Smoke and Dogs


Research from Colorado State University has found that secondhand tobacco smoke has a clear effect on dogs and increases their chance of disease.  One study shows that the more members of a household who smoke, the higher their dogs’ risk of developing certain kinds of cancer. Dogs with long noses are at an even greater risk of developing certain nasal and sinus cancer, as they expose more tissue to the carcinogens when they inhale. This also provides more area in which the carcinogens can accumulate. The carcinogens tend to build up on the mucous membranes of long nosed dogs so not as much reaches the lungs. Nasal cancer in dogs requires radiation therapy and even then the cancer is likely to recur.  Short and medium-nosed dogs are more susceptible to lung cancer, as the carcinogens more quickly pass the nose and settle in the lungs.  Dogs that are routinely exposed to secondhand smoke are 60% more likely to develop respiratory or skin allergies.  A recent study on the hair of 38 dogs exposed to secondhand smoke found that the levels of nicotine in the hair were similar to those found in the hair of children from smoking homes.


In addition, curious puppies or kittens or even adult dogs that may find and ingest cigarette butts can have serious toxicity from the nicotine.  Nicotine poisoning is a real concern anywhere that a pet may find cigarettes, cigarette butts, chewing tobacco, or nicotine gum or patches. Dogs, particularly puppies, tend to chew things up. Cats may find a cigarette butt to be a nicely sized pouncing toy worthy of chewing.


The toxic dose for nicotine in pets is 1/2-1 mg per pound of pet body weight, while the lethal dose is 4 mg per pound of pet body weight. A cigarette contains 9-30 mg of nicotine depending on the type of cigarette; while a cigarette butt contains about 25% of the nicotine of the original cigarette despite its deceptively small amount of tobacco. (Smoking seems to concentrate some of the nicotine in the tail end of the cigarette.) Cigars can contain up to 40 mg. Chewing tobacco carries 6-8 mg per gram while the gum has 2-4 mg per piece and patches have 8.3-114 mg. Smoking a cigarette yields only 0.5-2 mg of nicotine but eating one is a different ballgame as all of the nicotine becomes available for absorption into the body. One way to rephrase this is that a 40 lb dog would get very sick after eating one cigarette but would need 11 cigarettes to die from nicotine poisoning.


Symptoms of Nicotine Poisoning


Signs begin as quickly as one hour post-ingestion. Symptoms include:



  • Tremors

  • Constricted pupils

  • Drooling

  • Auditory and visual hallucinations

  • Excitement

  • Vomiting and diarrhea

  • Twitching, possibly progressing to seizures

  • Racing heart rate but slow heart rate with small doses

  • High blood pressure


If ingestion of a tobacco product is suspected, call your veterinarian or the Animal Poison Control Hotline immediately.  Immediate induction of vomiting and immediate care at your veterinarian could save your pet’s life.


Secondhand Smoke and Cats


Similarly to dogs, a study done at Tufts College of Veterinary Medicine found that cats exposed to secondhand smoke have an increased chance of developing a type of oral (mouth) cancer that is often seen in human smokers, squamous cell carcinoma. In a study published in the August 1 issue of the American Journal of Epidemiology, Dr. Elizabeth R. Bertone, an epidemiologist, and Drs. Antony S. Moore and Laura Snyder, both veterinarians, link second-hand smoke to cancer in cats, debunking a once-widely held belief that feline sarcoma is a byproduct of feline leukemia virus.  It is suspected that because of the grooming behavior of cats, they expose the mucous membranes of their mouth to the cancer-causing chemicals as they lick their coat.


Cats living with smokers are also twice as likely to develop malignant lymphoma according to studies done at Tufts University and the University of Massachussetts.  Malignant Lymphoma is a cancer that occurs in the lymph nodes and is fatal to three out of four cats within 12 months of developing signs of disease.  In cats, lymphoma has a poor prognosis, with cats rarely surviving more than six months even with aggressive chemotherapy. The report, entitled “Environmental Tobacco Smoke and Risk of Malignant Lymphoma in Pet Cats,” is the first of its kind.  Researchers admit that they are surprised by the connection. Smoking was not an initial target of the study.


“We were interested in lymphoma because it’s the most common cancer in cats and not very treatable,” says Dr. Moore. “At the same time, we wanted to figure out why we were seeing more feline lymphoma when leukemia virus was becoming less prevalent. We looked at flea control products, diet and other variables, and smoking came out very strongly. “It was very surprising. So many other things cause lymphoma in humans, smoking is often overlooked.”


Swallowing smoke


In sharing their lives and living space with humans, cats are exposed to many of the same environmental contaminants as their owners, including tobacco smoke. Exposure levels in indoor cats might read even higher than those of human household members because humans spend time away from the home, while cats are in the environment 24/7. This is because cats not only inhale smoke, they also ingest particulate matter by licking it from their fur while grooming, the study says.


“We believe that feline exposure patterns to environmental tobacco smoke may mimic those of young children living in households where adults smoke and where the children inhale tobacco smoke or ingest particulate matter by mouthing contaminated objects,” says Dr. Bertone, the study’s lead author.


Numbers


Feline lymphoma is the most common cancer in domestic cats, often involving their intestinal tracts. Tracking the disease, Dr. Moore and his colleagues conducted their case-control study on 180 cats treated at Tufts’ Foster Hospital for Small Animals between 1993 and 2000. Eighty of those cats were treated for lymphoma and 100 were treated for renal failure.


Adjusting for age and other factors, the study shows the relative risk for lymphoma for cats exposed to any household tobacco smoke rated almost two-and-a-half times more than that of cats not exposed. The risk increased according to the duration and level of the cat’s tobacco exposure, leaving those exposed five or more years at more than triple the risk of other cats, the study says.


The number of household smokers also appears as a factor with nearly a double relative risk for cats living with one smoker and four times the risk for cats living with two or more smokers. Cats living with humans smoking a pack or more a day had a three-fold increased risk compared to cats living in smoke-free households, the study says.


“I’m pleased with these numbers from the point of view that this has raised people’s sensitivity that the lifestyle choices they make affect everyone around them, including pets,” Dr. Moore says. “They might not stop smoking for themselves or their families, but they might for their cat.”


Secondhand Smoke and Birds


Anyone with a pet bird knows to avoid using Teflon-coated pans because of birds’ sensitive respiratory systems – so it’s no surprise that birds are also at risk for lung cancer, as well as pneumonia, from secondhand smoke.  A bird’s respiratory system is hypersensitive to any type of pollutant in the air.  The most serious consequences of secondhand smoke exposure in birds are pneumonia or lung cancer. Other health risks include eye, skin, heart, and fertility problems..


Conclusion


The good news is that many smokers are becoming aware of this problem and are becoming motivated to quit smoking. In a study published in Tobacco Control, researchers led by Sharon M. Milberger, ScD, of the Henry Ford Health System in Detroit, found that 28.4% of smokers who participated in an online survey said learning that secondhand smoke was bad for their pet’s health would motivate them to quit. And 8.7% said knowing the potential adverse health effects of secondhand smoke would spur them to ask their partners to quit.


For more information, visit www.avma.org or the AVMA Media Library at www.avmamedia.org for this podcast — Kick the Habit, for You and Your Pets — and video — The Great American Smokeout — along with dozens of other podcasts, videos and audio news releases and public service announcements. The video is also posted on the AVMA’s public video site, AVMA-TV, at www.AVMATV.org. …The American Legacy Foundation is challenging pet parents to quit smoking during the month of April, which is also Prevention of Cruelty to Animals Month. Research shows there are no safe levels of exposure to secondhand smoke for humans — and that goes for animals as well. One new study reveals that nearly 30 percent of pets live in a home with at least one smoker. . To better protect our pets, the American Legacy Foundation and ASPCA recommend that smokers “take it outside” when they light up. The foundation also provides resources to support smokers in their decision to quit, including BecomeAnEX.org, an interactive website with free tools and tips to help smokers develop a personalized plan for quitting – for their health and the health of their pets!!