Dropping a pound or two isn't necessarily a bad thing, especially if your pet's packing a few extra. But weight loss should be controlled, gradual and supervised by your veterinarian. Sudden, unexpected weight loss usually signals an underlying health problem. Cats, in particular, need frequent weight monitoring to prevent hepatic lipidosis, a debilitating liver disease.
Some pets lose weight in the heat of summer when rising temperatures curb their appetite. At the other extreme, you'll find some pets losing weight during frigid weather because they're burning more energy while trying to keep warm. Other common causes of weight loss include stress and lactation.
Healthy boarded pets may shed some pounds because of diet changes or the stress of a new environment, and nursing mothers burn more calories as their bodies produce milk. Although normal, these responses to environmental or lifestyle changes mean your pet uses and needs, more calories to meet increased energy requirements. Diet plays a crucial role in weight maintenance. Undernourishment and weight loss occur in pets who are fed poor-quality, inedible or spoiled food. Many underlying medical conditions such as dental disease, gastrointestinal disorders (including parasites), diabetes mellitus, liver or kidney disease, congestive heart failure and cancer make eating and absorbing nutrients difficult.
Other conditions, including hyperthyroidism, fever and chronic infections, increase your pet's metabolism and the rate she burns calories. The result can be dramatic weight loss.
What You Can Do at Home
A nutritious diet and lots of fresh water are your pet's best defenses against unwanted weight loss. Feed your pet the right amount of high-quality food that's appropriate for her life stage and activity level. And make sure she visits the veterinarian at least once a year for a thorough examination and parasite prevention.
When to Call the Veterinarian
See your veterinarian whenever your pet experiences unexplained weight loss. Call the doctor immediately if your pet exhibits additional symptoms such as vomiting, diarrhea, fever or increased thirst or urination.
Literally hundreds of conditions can cause weight loss in pets, so please be patient as the veterinarian makes his or her diagnosis.
Though some of these conditions are serious, most pets who have slimmed down quickly, soon return to their original weight with no complications.