Obesity is a common nutritional problem for dogs and cats, especially for females and older breeds. Overweight pets are often fed too much and lack adequate exercise. Obesity can be dangerous, for it often causes or worsens conditions such as heart and lung disease, diabetes, liver disease, and other illnesses which can shorten an animal's life. Many owners do not realize that their pets are overweight. A quick way to check for obesity is to place your hands lightly on your pet's back with your fingers extending downward around the chest. Without applying any pressure, you should easily be able to feel the ribs beneath your hands. If you cannot easily feel any definition of the ribs, your pet is probably overweight. This test should not replace a doctor's diagnosis, so if you are unsure about your pet's weight and health, contact your veterinarian.