Smoking is bad for pets too, the University of Glasgow said Tuesday, citing an ongoing study into the effects of second-hand smoke on dogs and cats. Research under way at the Scottish institution has found that pets living in a smoky environment have a higher risk of health problems including some animal cancers, cell damage and weight gain. “Pet owners often do not think about the impact that smoking could have on their pets,” said Clare Knottenbelt, professor of small animal medicine and oncology.