“Doc, my cat eats constantly but still keeps losing weight!”
While there can be any number of causes for this, in a middle-aged or older cat an overactive thyroid is always one of the potential reasons atop our list.
Thyroid glands produce hormones that regulate metabolism. But when they are enlarged and producing too much thyroid hormone, they rapidly increase a cat’s metabolic rate. This causes, among other things, a dramatic increase in heart rate and blood pressure, and an increased demand for nutrients. These kitties literally cannot consume enough calories to meet their bodies’ increasing demands.
Untreated hyperthyroidism can cause heart failure or organ failure, but many cats just waste away. I have seen adult cats weighing less than 4 pounds, caused by uncontrolled hyperthyroidism. Many owners mistakenly believe that as long as their cat has a healthy appetite, it is OK, but this kind of weight loss can be fatal.
Hyperthyroidism can easily be diagnosed by your veterinarian through simple blood tests. With an exam and additional blood work, your vet can also tell what organs may be affected and what treatment option would be best for your cat. Today’s treatments can involve daily medication, surgery to remove the enlarged gland, or radioactive iodine treatment to destroy the abnormal thyroid tissue. Each treatment has its pros and cons – so only you and your vet can decide which option is best for your pet.