Hyperthyroidism

The diagnosis of hyperthyroidism can be confirmed by running a blood test to determine the cat's thyroid hormone level.  Additional tests will also be performed to screen for other health problems that might show up in older cats and that might influence the treatment choice and prognosis

The treatment options discussed below offer advantages and disadvantages, which must be considered for each individual pet.

TREATMENT OPTIONS:

1. Medication:  Anti thyroid drugs can be used to control the signs of hyperthyroidism.  The medication works by blocking the production of the thyroid hormone. It does not destroy the tumor: therefore, it will not cure the disease.  However, it can effectively control the signs of hyperthyroidism when given daily.  Since therapy require giving the cat tablets every day (initially 2-3 times daily), we do not recommend this treatment if you can't give your cat oral medication.  It must be given diligently.  If drug treatment is interrupted, even for a day or two, hormone levels will increase and signs will return.
   
   
2. Surgery:  Surgery can be performed to remove overly active thyroid glands,  thereby curing the hyperthyroid condition.  Since your cat is older, there is some increased surgical risk.  However, in the majority of cats without concurrent medical disease, the risk is minimized.
   
   In order to achieve this , we must first control you cat's hyperthyroid condition with oral medication.  this take 3-6 weeks in most cases.  In the majority of hyperthyroid cats, both thyroid glands must be removed.
   
   Although this cures the hyperthyroid state, in many cats will require thyroid hormone supplementation  (usually once a day) following surgery to prevent hypothyroidism (a state of thyroid hormone deficiency).  Such thyroid hormone supplementation is usually required for a few months post operatively, but may have to be given for the remainder of the cat's life.
   
   A serious post-operative complication is hypocalcemia (low calcium levels in the blood).  This develops i about 5-10% of cats when the small parathyroid glands (located in and around the thyroid glands) are removed or when their blood supply is temporarily interrupted.  Parathyroid hormone is important in regulating calcium levels in the blood.  Cats must be kept in the hospital for 2-3 days following so we can watch for signs of low calcium levels, which include muscle tremors, stiffness or even convulsions.  Successful treatment of hypocalcemia includes daily administration of Vitamin D and calcium.  In the majority of cats, this medication can be discontinued within 2-3 months.
   
   
3. Radiation Therapy:  This is a therapy where radioactive Iodine is used to destroy the overactive thyroid tissue.  Since iodine is only utilized by the thyroid gland it is very selective for thyroid tissue and spares the parathyroid glands.  There are special handling requirements after the procedure is performed but they are handled by the veterinary staff while your cat is hospitalized, usually for 7-10 days.  This is the most successful method of treating hyperthyroidism and the complication rate is very low.  We can give you a referral to the closest Radiation Oncologist

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