If your dog has been diagnosed with canine thyroid disease, that means there is not enough thyroid hormone circulating in their system to maintain healthy body functions. Hypothyroidism (low-functioning thyroid) is the most common endocrine disease in dogs, and is easy to treat.
FACTS REGARDING CANINE THYROID DISEASE
Some of the diseases and conditions associated with canine thyroid disease can be quite serious, including: enlarged esophagus, ruptured ligaments, testicular atrophy, heart disease, excessive bleeding, and corneal ulcers.
Because the thyroid gland is important to healthy bodily functions, and governs the body’s basic metabolism throughout the dog’s lifetime, failure of the thyroid means trouble for the body, and thyroid imbalance must be addressed!
Clinical signs of thyroid disease are widely varied, and can include (among others): weight gain, lethargy, mental dullness, skin abnormalities, weakness, decreased exercise tolerance, and sometimes behavioral changes – sweet dogs can become aggressive, steady dogs may become fearful.
In the past we relied upon testing one measurement only for diagnosing hypothyroidism, the T4 level. New studies, however, indicate that by the time the T4 level is measurably low, 70% of the thyroid gland may be destroyed. Additionally, T4 levels are very easily influenced by other illnesses and by use of many common medications. Consequently, we recommend a more thorough test which measures several other thyroid markers, including the “thyroid gland autoantibody”, or TgAA. TgAA is especially important because the most common cause for canine hypothyroidism is that the dog’s immune system, for unknown reasons, attacks and destroys its own thyroid gland. The presence of TgAA tells us that the dog will soon be hypothyroid because of this inappropriate action of its immune system.
Early detection and treatment of thyroid dysfunction is key in preventing the most serious complications of hypothyroidism.
Another important reason to know if your dog has elevated TgAA is that dogs who have this condition are also more likely to develop other immune-mediated disease.
KEY FACTORS IN TREATING HYPOTHYROIDISM
Dogs generally respond very well to thyroid hormone replacement. Unfortunately the “natural” thyroid supplements do NOT by themselves serve to replace what is missing. Thus we do use a synthetic replacer as we need to be sure we are correcting the deficiency.
It is important to give this medication 1 hour before feeding, or 3 hours after feeding to ensure optimal absorption of the medication.
We suggest giving the morning pill immediately upon starting your day, then feeding your dog right before you leave for your work day. When you return home from work, give your dog their second dose of the medication, and feed them an hour later. Alternately, you can feed the dog right when you get home from work, and give them their medicine right before bedtime. It is more important to give the medication separate from their food than to give it exactly 12 hours apart. Twice daily dosing is essential, however.
THYROID TESTING IN DOGS
Hypothyroid dogs who are being treated for their disease will need to be retested to be sure the disease is being adequately managed. We will need to retest your dog’s bloodwork approximately 6 weeks after they begin treatment to correct their deficiency.
It is imperative that we draw the blood sample 4-6 hours after the morning pill has been given in order for us to accurately measure how effectively they are being treated as this will reflect the levels of hormone in their blood when it is at its highest.
After this 6 week retest, we typically will only need to retest your dog once a year unless their blood levels suggest that we need to change their medication dosage, in which case we will need to test again sooner.
SPECIAL INFORMATION FOR BREEDING DOGS
ALL dogs who will be bred should have a baseline thyroid hormone panel 6 weeks after the first estrus cycle for females, or at 9-10 months for males. They should be tested yearly thereafter. Female dogs with TgAA can pass it along to their offspring and thus perpetuate this immune-mediated disease.
