The thyroid gland is located in the neck. The function of the thyroid gland is to release thyroid hormone which controls the metabolic rate of cells within the body. An overproduction of thyroid hormone (hyperthyroidism) will increase the body's metabolism whereas an underproduction of thyroid hormone (hypothyroidism) will slow the body's metabolism.
Hypothyroidism is a result of an underproduction of thyroid hormones which results in a decreased metabolic rate of the body.
WHAT ARE THE CHANCES OF MY PET HAVING HYPOTHYROIDISM?
Natural occurrences of hypothyroidism are common in dogs but rare in cats.
Medically induced occurrences of hypothyroidism caused by the inappropriate dosing of thyroid medication can occur in both dogs and cats. That is why it is important to follow routine thyroid testing schedules determined by your veterinarian.
Cats can develop hypothyroidism following radioactive iodine therapy or removal of the thyroid gland.
WHAT ARE THE CLINICAL SIGNS OF HYPOTHYROIDISM?
Hypothyroidism does not produce specific clinical signs and may resemble other diseases. Typically, there are multiple symptoms that prompt a veterinarian to suspect hypothyroidism. General signs include:
lethargy - pet may sleep more and be less active, not wanting to participate in normal play or other activities
increased weight - due to the decrease in metabolic rate of the body, the pet does not burn as many calories which results in an increase in weight
dermatological changes - changes to the skin and hair coat can occur; increases in skin infections and scratching may be noted; hair coat may become sparse and hair loss can occur; chronic ear infections can occur
cardiac signs - hypothyroid patients can have a low heart rate
HOW IS HYPOTHYROIDISM DIAGNOSED?
When hypothyroidism is suspected, the diagnosis is confirmed through a thyroid profile blood test. The thyroid profile is performed at the Michigan State University laboratory which is recognized throughout the United States as the leading testing facility for thyroid disease. The thyroid profile runs eight separate panels that are used to evaluate the patient's production of thyroid hormone.
WHAT IS THE TREATMENT FOR HYPOTHYROIDISM?
Hypothyroidism is a disease that can be controlled with the long-term use of oral medication. A thyroid hormone tablet is given daily to supplement the levels of thyroid hormones being naturally produced by the body. Usually, improvement in clinical signs such as lethargy are noticed within four to six weeks. Dermatological changes to the skin and coat may take several months before noticeable improvement is seen. It is important that thyroid hormone levels are monitored through periodic blood tests to make sure that continued therapeutic levels are maintained. Maintenance thyroid profiles are scheduled so that a blood sample is drawn six to eight hours after the thyroid medication is given.
IF YOU ARE CONCERNED THAT YOUR PET MAY BE SHOWING SIGNS OF THYROID DISEASE,
PLEASE SCHEDULE AN APPOINTMENT TO HAVE YOUR PET EXAMINED BY ONE OF OUR VETERINARIANS.
Hyperthyroidism is a result of an overproduction of thyroid hormones which results in an increased metabolic rate of the body.
WHAT ARE THE CHANCES OF MY PET HAVING HYPERTHYROIDISM?
Natural occurrences of hyperthyroidism are very common in older cats but very rare in dogs.
Hyperthyroidism occurs in cats 4 to 22 years of age with 90% of affected cats being over 10 years of age.
WHAT ARE THE CLINICAL SIGNS OF HYPERTHYROIDISM?
Clinical signs associated with hyperthyroidism include
increased appetite along with weight loss - patients tend to lose weight because they are not able to take in enough food calories to offset the increased body metabolism caused by the hyperthyroidism
changes in activity - hyperthyroid patients may show increased signs of irritability, restlessness or even hyperactivity; in some advanced cases there may be signs of generalized weakness and lethargy along with a decrease in appetite
unkempt coat - hyperthyroid cats have a tendency to stop grooming themselves when they are feeling ill and their hair coat will start to appear unkempt and scruffy in appearance
cardiac signs - hyperthyroid patients can have a rapid heart rate that can cause hypertension (high blood pressure) which can result in chronic renal failure (kidney disease) and untreated hyperthyroid patients can develop cardiomyopathy (a thickening of the heart muscles) which can result in congestive heart failure
polyuria/polydipsia - increase in water intake and increase in urine output
HOW IS HYPERTHYROIDISM DIAGNOSED?
When hyperthyroidism is suspected, the diagnosis is confirmed through a thyroid blood test. The thyroid profile is performed at the Michigan State University laboratory which is recognized throughout the United States as the leading testing facility for thyroid disease. The thyroid profile runs eight separate panels that are used to evaluate the patient's production of thyroid hormone.
WHAT IS THE TREATMENT FOR HYPERTHYROIDISM?
Treatments for hyperthyroidism include
Methimazole: Long-term drug therapy that inhibits the production of thyroid hormone. It is important that thyroid hormone levels are monitored through periodic blood tests to evaluate how well the medication is controlling the thyroid disease.
Radioactive Iodine: This is a noninvasive procedure that destroys hyperfunctioning tissue without affecting normal thyroid tissue. Radioactive Iodine treatment is performed at a specialty center. Patients must be hospitalized for one to two weeks following the treatment until their surface radiation falls to a safe level.
Surgical excision: A surgical procedure is performed to remove one or both thyroid lobes. If only one gland is removed, the patient's thyroid hormone levels will be monitored to assess that the remaining gland is not over producing. When both glands are removed, the patient will be treated as a hypothyroid patient with a thyroid hormone supplement.
IF YOU ARE CONCERNED THAT YOUR PET MAY BE SHOWING SIGNS OF THYROID DISEASE,
PLEASE SCHEDULE AN APPOINTMENT TO HAVE YOUR PET EXAMINED BY ONE OF OUR VETERINARIANS.