Cat being carried at pet fair in Bogota, Colombia
Second-hand smoke causing weight-gain and cancer in petsDiana Sanchez/AFP/Getty Image

It is often something that pet owners overlook but researchers have given a frank analysis on how bad second-hand smoke can be for their domesticated animals. A team from the University of Glasgow says cats and dogs that live in a household with smokers are more likely to suffer from negative health conditions such as weight gain, cell damage and even some forms of cancers than those living in smoke-free environments.

While the research is still ongoing, with the paper not set to be published until 2016, the team heralding from Scotland has given a few insights into the study. By analysing the testicles of castrated dogs, they found a gene that signifies cell damage was more prevalent in dogs living in a smoker's household. Furthermore, dogs who live in such homes are more likely to gain weight after neutering.

However, the results showed "cats are even more affected" than dogs due to their grooming methods, which sees the nicotine become attached to their fur and essentially consumed during their cleaning methods.

Victoria Smith MRCVS said: "Our work so far has shown that cats take in significant amounts of smoke and even having outdoor access makes very little difference. Owners who consistently smoked away from the cat did not protect their cat from exposure but did reduce the amount of smoke that was taken into the body."

Clare Knottenbelt, professor of small animal medicine and oncology at University of Glasgow, added: "Pet owners often do not think about the impact that smoking could have on their pets. Our findings show that exposure to smoke in the home is having a direct impact on pets. It risks ongoing cell damage, increasing weight gain after castration and has previously been shown to increase the risk of certain cancers."