PetMeds® Treating Hyperthyroidism in Cats
Hyperthyroidism or an overactive thyroid is the most common hormonal disease seen in older cats. The most common symptoms include weight loss (despite an increased appetite), as well as increased thirst and urination. Some cats may become more restless and vocalize more, as well as develop inappropriate urination or defecation. If left untreated, hyperthyroidism can lead to high blood pressure, kidney damage or secondary heart disease.
Diagnosis is usually made by blood measurement of Thyroid levels, usually a T4 in conjunction with a free T4. There have been traditionally three options of treatment. The most common form of treatment is with a prescription medicine known as Methimazole. This medicine must be given daily to twice daily, and periodic thyroid level blood monitoring is needed every 3-6 months after initial control is obtained, , as well as monitoring of the blood count, and liver/kidney function to make sure there are no ill effects of the medication.
Occasionally cats will become lethargic, vomit, or lose their appetite on Methimazole. However, with dose adjustments, most cats do tolerate Methimazole quite well, which needs to be maintained for the life of the cat. Other options of treatment include using radioactive iodine, which is preferred by many as a single dose curative treatment in most cases. Surgical removal of the thyroid gland is no longer as common, due to surgical risk in many of these older cats.
In my experience there are not that many effective supplements for cats to treat the overactive thyroid, however, if your cat will accept cooked brassica veggies like broccoli or kale, these can sometimes have a thyroid-lowering effect. The herb bugleweed has been used by some, but data as to efficacy is limited.