Causes of Rapid Weight Loss in Cats

Keeping your cat healthy means feeding it a balanced, nutritious diet. A cat that receives proper care and nutrients should maintain its body weight. If you feed your cat high-quality food and it suffers from rapid weight loss, take it to a veterinarian for a checkup as soon as possible. It's possible that the animal is suffering from a serious medical condition.

  1. Feline Hyperthyroidism

    • Feline hyperthyroidism stems from overactive thyroid glands. The illness is most common in older cats, with the majority of affected cats over the age of 10, according to the Washington State University College of Veterinary Medicine. In addition to rapid weight loss, key signs of feline hyperthyroidism include a dull or unkempt coat, an increase in appetite, restlessness, increased thirst and urination, vomiting, weakness and problems breathing. If your cat has hyperthyroidism, it may need anti-thyroid medications for the rest of its life. In some cases, cats with hyperthyroidism need surgery or treatment with radioactive iodine.

    Diabetes Mellitus

    • Cats develop diabetes mellitus when their bodies either cannot produce or cannot use insulin. The disease occurs most often in older male cats. Cornell University's College of Veterinary Medicine website attributes diabetes-related rapid weight loss to the breaking down of protein and fat for energy. This occurs when a cat's body receives insufficient insulin. A cat who eats often yet loses weight, drinks more water than normal and urinates frequently may have this disease, which is either insulin-dependent or non-insulin-dependent. Treatment often requires injections of insulin, oral medications or a special diet.

    Feline Leukemia Virus

    • An infectious virus causes feline leukemia, or FeLV. Feces, saliva, urine, blood and mucus may all contain the virus. Most cats become infected through bites from an infected cat, according to the University of Arizona Institutional Animal Care and Use Committee. The group claims that 30 percent of exposed cats cannot fight off FeLV, and become permanently infected. Most of these cats die within a few years. The main symptoms of FeLV are rapid weight loss, vomiting, diarrhea, eye infections and anemia. Treatment for feline leukemia focuses on treating the cat's symptoms, since there are no specific treatments or cure for the disease itself. There are, however, vaccines for cats that are not yet infected.