Sandra R. Merchant, DVM, Diplomate ACVD 

Carol S. Foil, DVM, Diplomate ACVD


Healthy skin and a normal hair coat are the same result of many factors, both external and internal.  There are several glands in the body responsible for the production of hormones that are vital for the regulation of other body functions as well as a normal skin surface and hair coat.


Hypothyroidism results from a lack of thyroid hormone production by the thyroid glands, which are located in the neck, near the voice box.  It is seen most commonly in middle-aged to older dogs.  Affected dogs become easily fatigued, sleep for longer periods of time, are often dull in their attitude and may seek a warm area in cold weather. Slim breeds of dogs may seem puffy or over-weight,  as the skin becomes thickened in hypothyroidism. The hair coat becomes dry and looses sheen, the color dulls and the hair may become very sparse, especially in areas of friction, with darkening of the skin. Clipped hair may not regrow. Affected dogs may become prone to skin infections and poor wound healing, as well as many internal health problems.


Diagnosis of hypothyroidism depends on taking one to several blood tests to measure levels of thyroid hormones.  Tests may include measuring total T4, free T4, TSH or a TSH stimulation test. In some cases, diagnosis can be difficult and repeated testing is necessary.


Treatment is by administration of oral thyroid hormone supplementation.  There is generally a rapid improvement in your pet's activity once treatment is started.  However, regrowth of the hair and lightening of the skin may take several months.  Occasionally, a pet may experience sensitivity to the amount of thyroid supplementation given.  Signs associated with this include a rapid heart beat rate, increased water consumption/urination, change in temperament of weight loss.  Please contact us if any of these signs become evident. Most dogs on supplement should have blood tests done to ensure adequate supplementation every 6 months. Treatment is life-long as there is no true cure for hypothyroidism.



Give ______ tablet(s)        times a day.  


 Drug                     Strength                

Please make a recheck appointment for        weeks,         hours after the morning medication is given, so that post treatment thyroid level can be measured. In some cases both pre- and post-treatment levels will need to be measured.  Your veterinarian will explain this.