By Dr. Heather Kovac
The Patient
Mittens, a 15 year old spayed female domestic shorthair cat, was presented by her owner for weight loss and an increased appetite.
The Case
Over the past few months, Mittens had been progressively losing weight despite an increased appetite. She seemed more agitated, especially at night, and was also drinking more water than usual. On physical examination, she had lost 2 pounds, had moderate dental disease, a rapid heart rate, and a small nodule under the skin on her throat area.
I recommended routine labwork to assess her metabolic health and determine the cause of her symptoms. Her panel showed a mildly elevated liver enzyme called ALT and her thyroid hormone (T4) was very elevated at 12.5. Normal is around 2.5 in cats. Mittens was diagnosed with hyperthyroidism.
Hyperthyroidism is caused by a benign nodule/mass on the thyroid gland in the neck of the cat. The nodule produces excessive thyroid hormone which drives the metabolism in the body. Hyperthyroid cats have fast heart rates, increased blood flow to the organs, and added strain on the heart. Their metabolism is so fast that they need a massive amount of calories to maintain body weight. It is almost as if their body is running a marathon every day. This is not sustainable and so these cats lose weight rapidly. Hyperthyroid cats tend to have trouble sleeping and are restless at night and typically beg for food by meowing/yowling loudly at their owners.
The Treatment Plan
Mittens was started on an oral medication called methimazole which prevents the thyroid hormone from being produced. We typically do not have to surgically remove the nodule from their thyroid gland as it is benign. Cats typically respond within a few weeks to the medication. It was recommended to have Mittens return for a follow up in about 3 weeks.
The Outcome
At this visit, she had gained 1 pound, was not as ravenous, was sleeping better, and the owners were happy. Her recheck labwork revealed a T4 level of 2.8. Mittens responded well to her medication. Treatment is for life but thankfully, most cats with this disease love to eat and the pill is small enough to hide in the food. Cats can live for many years with this disease if treated appropriately.
The Takeaway
If left untreated, hyperthyroidism can lead to heart complications that can be deadly. It can also cause high blood pressure that can lead to retinal detachment and blindness. If you suspect your cat may be showing signs of hyperthyroidism, please get a check up right away!
The Drake Center for Veterinary Care is an AAHA-accredited animal hospital located in Encinitas, CA. The Drake Center loves being a source of information for all pet owners across the country however if you have any questions regarding pet care and do not live in Encinitas, CA or surrounding cities, we encourage you to contact your local veterinarian.