Could second-hand smoke be hurting your household pets?
A Japanese study has found that dogs admitted to a veterinary hospital with chronic cough were much more likely to be from homes with smokers than from non-smoking households.
Dr. Yoshiki Yamaya, lead author on the study, told Decoded Science that the number of dogs involved in the study who showed evidence of Passive Tobacco Smoke Exposure (PTSE) was much higher than expected when compared to the percentage of people in Japan who smoke.
Effects of Secondhand Smoke on People
The Centers for Disease Control and Prevention (CDC) website states that research has linked Passive Tobacco Smoke Exposure (PTSE) to heart disease and lung cancer in adults, and a variety of health problems in children, ranging from ear infections to respiratory infections and increased risk of Sudden Infant Death Syndrome.
But the link between PTSE and respiratory disease in dogs has not yet been completely established. New research sheds light on the issue, and further research could provide even more information about the dangers of secondhand smoke for pets.
Study Assesses Tobacco Smoke Influence on Canine Respiratory System
Dr Yamaya’s team evaluated 43 dogs, some from households where they were exposed to tobacco smoke, and others from non-smoking households. Exposure to secondhand smoke was confirmed through serum cotinine levels. While nicotine is rapidly eliminated from the body, scientists can detect its metabolite cotinine for several days after exposure.
Dogs with cotinine levels below 0.21ng/mL were considered unexposed and those with higher levels placed in the exposed group. Brachycephalic (short-nosed) breeds and dogs with bronchomalacia (weak or collapsing trachea) were left out of the study, but the authors note that all of the dogs with bronchomalacia were classified as having PTSE during preliminary assessment.
The dogs were then placed in a barometric chamber to evaluate respiration. Dogs with PTSE had increased airway limitation as compared with unexposed dogs. An interesting finding in the study was the large percentage of dogs (67%) who had PTSE. Only 20-30% of people in Japan are smokers, so the researchers expected to find a similar percentage of dogs with PTSE.
How Does Secondhand Smoke Affects Dogs? More Research Planned
While Dr. Yamaya told Decoded Science that she suspects that PTSE may trigger respiratory disease, the team was not able to determine whether it was the initiating factor in any of the animals in this study, as only dogs admitted to the Animal Medical Center of Nihon University for chronic cough were included.
In addition to finding out whether secondhand smoke does trigger respiratory disease, Dr. Yamaya went on to say that she is interested in looking at how individual animals may vary in their sensitivity to PTSE, and researchers also plan a study to increase understanding of the relationship between other allergic diseases and PTSE.