Thyroid Problems in Cats

In cats, thyroid problems have more to do with an overactive thyroid rather than an underactive one. Cats are more likely to have hyperthyroidism, which mean the thyroid is producing too much thyroid hormone and secreting it into the blood.

What causes feline hyperthyroidism?

Feline hyperthyroidism is caused by an increased levels of thyroid hormone, due to enlarged thyroid gland. in the amount of thyroid hormones produced by enlarged thyroid glands. Usually caused by an adenoma, or benign growth on the thyroid. Rarely is this growth cancerous.

Symptoms:

• Weight loss


• Increased appetite


• Increased thirst


• Restlessness


• Unkempt hair with excessive shedding and matting


• vomiting and/or diarrhea


• Rapid heart rate


• Heart murmur


• Respiratory difficulty

Every cat is different and may not exhibit all of these symptoms, but if your cat is middle aged and is showing some of these signs and symptoms, contact your vet for testing and diagnosis of possible feline hyperthyroidism.

Treatment:

Once your cat has been determined to have a hyperactive thyroid problem, these treatment options are available, which include:

1. Radioactive iodine


2. Thyroidectomy (removal of the thyroid gland)


3. Anti-thyroid medications.

Treatment choice depends on your cat's current health status. The kidneys, liver, and heart will need to be monitored during the whole course of therapy. The most recommended treatment for a cure is radioactive iodine treatment or thyroidectomy. Both treatments involve the administration of thyroid hormone replacement for the rest of your pet's life.

Radioactive iodine (RAI) treatment is usually the best option because it avoids the risks associated with surgery. This treatment is also preferred for ectopic thyroid tissue (thyroid tissue located somewhere other than the thyroid gland), which occurs in a small number of cats afflicted with hyperthyroid disease.

If the cat has no risk for anesthetics, thyroidectomy can still be performed. Cats as old as 18 years old may still be considered for this procedure, if there are no other underlying conditions that may be contraindications for surgery.

During surgery, both thyroid glands, located in the front of the neck on both sides of the trachea (windpipe), are evaluated, removed, and taken for biopsy. The surgeon takes great care to avoid damaging the parathyroid glands, which are located in close proximity to the thyroid glands. The parathyroids control calcium levels in the body, therefore, these levels must be monitored as well during the post-op phase of recovery.

Complications can include nerve damage and voice changes. Additionally, hypothyroidism (low thyroid hormone levels) can develop due to thyroidectomy, which may include:

• Poor activity,


• Weight gain


• Hair loss

Treatment for feline hyperthyroidism involves anti-thyroid medication, such as methimazole (Tapazole), the most commonly used. It acts to suppress thyroid hormone production. Side effects of this medication include:

• Poor appetite


• Vomiting


• Lethargy and


• Skin rashes


• Bone marrow suppression


• Liver toxicity

Hyperthyroidism is a serious ailment for cats, but there are effective treatments available to keep your cat living a normal healthy life.

by Barb Hicks, RN/LMT