Fat cats and dog pounds.

• Position: Obesity in pets

Dogs and cats often share traits with their humans, including weight problems. Between 25 percent and 40 percent of America's pets are obese, according to George Fahey, a professor of nutrition at the University of Illinois Animal Sciences Department. The proportion of obese adults in the U.S. is similar, at 30 percent. Fahey cites two basic reasons that pets are getting heavier: too little exercise and too many calories, problems also shared by humans. It is now possible to indulge pets with...