You've certainly noticed the extra girth around your midsection, but have you noticed that your furry friends have put on some weight? If not, it's time to check and perhaps include Fido and Fluffy in your weight-loss efforts. Veterinarians estimate that about 35 percent of pets are overweight or obese. Even a small amount of weight can add up on a pet's frame. A medium-sized dog, like a cocker spaniel, who carries 5 pounds of extra weight is similar to a woman carrying 25 extra pounds. Four extra pounds on a cat is the equivalent of 45 pounds on an average-sized woman. So how do you know if your pet needs to lose a little? Feel around his midsection.