Elderly Cat: Big Appetite and Dilated Pupils could mean Thyroid Tumors

Feline Senior Citizen needs a Thorough Geriatric Workup

I have a senior Siamese going on 17 years. She has eaten Iams dry food all her life, turning her nose up at anything else including chicken and fish. All of a sudden she quit eating and it seemed that her mouth was bothering her. I had her teeth cleaned and was given antibiotics for possible mouth problems. She seemed to feel better, but wants to now eat canned food and she begs for food while I am eating, which she never did before. She does not seem sick, but she used to have beautiful baby blue eyes and now they are dilated all the time. She drinks, plays and uses her box with no issues. Please help, I miss her baby blues!!!!

Dr. Nichol:
You must have taken mighty good care of your sweet Siamese senior for her reach 17.  Routine maintenance like dental cleaning makes a real difference but age-related problems are inevitable. Changed eating habits and persistently dilated pupils are important signs.

The practice of evidence-based medicine requires the skills of a sleuth. Veterinary medicine is particularly challenging because our patients don’t speak a human language. Gradually advancing kidney failure is the most common disease of older kitties but your girl’s symptoms suggest hyperthyroidism. Studies have shown that as many as 20% of cats over age 9 years have benign thyroid tumors that produce excessive amounts of thyroid hormone. Voracious appetites, weight loss, and racing heart rates (over 200 beats per minute) are common signs. Dilated pupils and behavior changes (hyperactivity, aggression) are sometimes seen.

I agree with your sense of urgency; the health of an elderly pet is fragile at best. Your girl needs a thorough geriatric evaluation to include a physical exam, chemistry panel, urinalysis, and a blood count. A thyroid profile would be essential. I also recommend chest and abdominal x-rays to help screen for malignancy.

Your cat’s history may also reveal valuable clues. Her improvement following dental cleaning and antibiotic treatment suggests a still smoldering infection. Dental x-rays could expose a hidden root abscess. Feline hyperthyroidism and dental problems are “good” diseases because they respond well to treatment. Forget watchful waiting. Do whatever it takes for your special cat.