Untreated Hyperthyroidism

Progressive and untreated hyperthyroidism can lead to

• Effects on internal organs and severe metabolic dysfunction can develop ultimately leading to an untimely death.
• Increase in blood pressure which can cause damage to kidneys and lead to retinal detachment.
• Further weight loss and muscle wasting.
• Increase in hear rate which an lead to heart disease.
• Organ failure and a decrease in quality of life.

Radio Iodine Treatment

Radio Iodine Treatment is the preferred treatment for feline hyperthyroidism. There is a 98% success rate of CURING your cat of hyperthyroidism with ONE treatment. The Radio Iodine Treatment is an oral dose given by trained veterinary personnel in a treatment center hospital. This treatment avoids surgery, anesthesia and the administration of anti-thyroid drugs. Please visit our Radio Iodine section for a more in depth look into the treatment.

Surgical Removal of Thyroid Gland(s)

Surgical removal of the thyroid gland(s) cures the hyperthyroid condition by removing part or all of the thyroid gland(s). By removing the thyroid gland(s), the surgeon is also removing the source of the increased thyroid hormone. Surgery is generally effective.

Considerations and Side Effects of Surgical Removal of Thyroid Gland(s)

• Hyperthyroid patients are at an increased anesthetic risk. Patients will have to undergo general anesthesia for this procedure.
• Post- operative complications are not uncommon.
• Due to the location of the thyroid and parathyroid glands- it is common that they parathyroid gland is damaged during surgery which results in the need for calcium supplementation for the duration of the cat’s life.
• Considerable risk that surgery will not completely cure the hyperthyroidism.

Medical Management with Methimazole/ Tapazole/ Felimazole

This is an oral medication given 2-3 times daily for the life of the patient.
This oral medication will only control the hyperthyroidism, it will not cure it. Oral medication works by blocking the thyroid hormone secretion, but will not remove or destroy any part of the thyroid tumor. It can become difficult to maintain normal thyroid levels in the blood, as the tumor will continue to grow and subsequently continue to produce more thyroid hormone. After years of grown, it is possible for benign thyroid tumors to undergo malignant transformations.

Considerations and Side Effects of Anti-Thyroid Medication

• Some cats are difficult to medicate
• Owners are cautioned to wear gloves while administering as any accidental ingestion could cause a lowering of the owner’s thyroid level.
• Medication only blocks the thyroid hormone- it does not stop the grown of the tumor. When the tumor becomes larger- medications will no longer control the thyroid hormone.
• Side effects of oral medication can include: loss of appetite, skin lesions, vomiting, bone marrow suppression and elevated liver values.
• Use of this medication will require frequent re-testing of the thyroid hormone to determine the ideal dose for each patient.
• Due to its side effects, routine monitoring (CBC, kidney values, liver values and blood pressure) is recommended every 1-3 months for the life of the patient.

Medical Management with Prescription Diet

The iodine-deficient diet is a relatively new management option for feline hyperthyroidism available in prescription form (dry and canned) only through veterinary offices. Iodine is an element required for normal health. In the body, iodine is used primarily by the thyroid gland to produce the thyroid hormone. Iodine-deficient diets work by “starving” the thyroid gland of iodine which in turn will lower the production of thyroid hormone. Iodine-deficient diets do not treat the thyroid tumor itself.

• Palpability issues- getting feline patients to eat the diet.
• Low in protein- fails to meet nutritional needs of feline patients *ask your veterinarians for more information regarding feline nutrition and feeding recommendations*
• NO OTHER FOODS OR TREATS CAN BE GIVEN
• Non- hyperthyroid cats cannot be fed this diet. Need to separate cats for feedings.
• Requires thyroid hormone monitoring to ensure effectiveness.
• Does have limited side effects when compared to oral anti-thyroid medication.
• Thyroid gland tumor will continue to grow.