Causes of a Cat Losing Weight and Being Thirsty

As cats age, they are prone to many of the same aging-related disorders as humans. Cats are notorious for hiding early symptoms of illness, and often their owners do not realize anything is amiss until the disease is well advanced. This is why it is vitally important to bring your cat to the vet at the first sign of illness. A cat who is losing weight and drinking excessively is usually diagnosed with either diabetes, kidney disease, or hyperthyroidism.

  1. Diabetes

    • Diabetes occurs when the cat's pancreas no longer produces a sufficient amount of insulin to control glucose levels. The extra blood sugar travels through the kidneys to be excreted in the urine, and water follows. This causes the cat to urinate more frequently than usual, which depletes her organs of the water they need to function, so she will drink more water. Increased water consumption combined with improper glucose control keeps her body from getting the necessary nutrients from her food, so despite a ravenous appetite, she will still lose weight. Diabetes is easily diagnosed with blood and urine tests, and a simple diet change controls the blood sugar sufficiently for most cats. Some cats, however, require daily insulin injections.

    Kidney Disease

    • Kidney disease is very common in older cats. As the kidneys begin to work less efficiently, they must work harder to filter waste from the blood. This results in more frequent urination in especially large amounts, and increased water consumption as the cat tries to stave off dehydration. The dramatic increase in the amount of fluid traveling through the cat's body results in the dilution and premature excretion of important nutrients. This loss of protein will cause her to lose weight. Kidney disease is diagnosed through a combination of blood work, urinalysis, and x-ray or ultrasound, and is eventually fatal. Aggressive hydration therapy, combined with potassium supplements and a diet to take stress off of the kidneys, can make the cat more comfortable.

    Hyperthyroidism

    • Hyperthyroidism is a condition in which the cat's thyroid gland produces too much hormone, and is common in cats over ten years of age. Chemicals produced by the thyroid glands are important for the proper function of every major organ, so symptoms can be as varied as poor coat, trouble breathing, and fast heart rate. The most common symptoms presented are weight loss despite a good appetite, increased water consumption, and increased urination. Hyperthyroidism is diagnosed by a blood chemistry profile, and is most commonly treated with life-long medication. If the cat's kidney's are still performing up to par, radiation therapy or surgery to remove the damaged part of the thyroid may be options.