Passive smoking and its devastating effects have been highlighted in recent years in humans, but also spare a thought for our pets that are exposed to cigarette smoke too.

Research has shown that dogs and cats suffer from the effects of tobacco smoke.

Lymphoma is the most common cancer in cats. Only feline leukaemia virus and feline immunodeficiency virus were known to play a role in causing the disease.

"The reason Lymphoma was looked at was because that it is so common, and the ability to treat it is just not very good," Dr. Moore said. "Twenty-five percent of cats that have it, live no more than a year with chemotherapy."

The researchers tested a number of possible cancer risks, including diet, spay and neuter status, age, sex, breed, grooming, home characteristics, and the use of flea control products, shampoos, and oral medications. Only one factor, smoking, was associated with the cancer, in a significant manner

Cats that spend a lot of time indoors in a smoking household not only inhale cigarette smoke but also ingest it as toxic chemicals from the smoke accumulate in the fur and are more likely to develop malignant lymphoma which can kill within a year.

Dogs are more likely to develop serious conditions such as asthma, bronchitis, nasal and sinus cancer as well as lung cancer if they are living with smokers.