This post is going to be one that is near and dear to me, involving my favorite group of cats – senior kitties!
Hyperthyroidism, or an overactive thyroid gland, is an extremely common disease in older cats. The two thyroid glands are located next to the trachea in the neck. The thyroid is an endocrine organ, so it secretes hormones, specifically thyroid hormone, which helps regulate metabolism. An overactive thyroid is common in cats, while an underactive thyroid is more common in dogs and people.
Symptoms of hyperthyroidism can be blamed on an increased metabolism, including weight loss, more vomiting than usual, eating more than usual, talking more at night, sometimes diarrhea, and hyperactivity. Many times when we see an older cat having a really great appetite and playing with toys she hasn’t played with in a while it seems like a great thing! Unfortunately, sometimes that behavior is a sign of an underlying problem. Fortunately, hyperthyroidism is usually pretty straightforward to diagnose, and usually relatively easy to treat.
When your veterinarian examines your older cat, she will usually try to feel the neck for enlarged thyroid glands. In addition, your hyperthyroid cat may have lost weight, and have an increased heart rate. If thyroid disease is suspected, routine bloodwork with measurement of thyroid levels will be done. If the thyroid level is elevated, the diagnosis is made. If left untreated, uncontrolled thyroid disease will lead to further weight loss, heart disease, and kidney disease. Fortunately, treatment options are readily available.
There are several options for treatment of hyperthyroidism, including medication, surgery, and a special diet. The treatment of choice is a single dose of radioactive iodine, which destroys the diseased thyroid. Cats who have this treatment are cured, and do not have to take hormone replacement. Radioactive iodine must be administered at a special facility, so sometimes it is not an option for some owners. Your veterinarian can help you make the best decision. All cats when first diagnosed should be started on medication, because if the thyroid disease has been present for a long time, it can lead to damage to the kidneys that doesn’t show up until after the thyroid is regulated.
Usually cats who are affected by hyperthyroidism typically are over 10 years old, but we have seen it in cats as young as 8 years old. Thyroid disease is something that should be screened for regularly as your cat gets older. If your cat is diagnosed with hyperthyroidism, just remember that it’s very treatable, and you have lots of options!