Why Your Dog’s Anti-Thyroid Antibody Test Is Positive

Why Your Dog’s Anti-Thyroid Antibody Test Is Positive

Ron Hines DVM PhD

See What Normal Blood & Urine Values Are

The Causes Of Most Abnormal Blood  & Urine Tests

See How Tests Are Grouped

Anti-Thyroid Antibodies In Your Pet’s Blood

Your veterinarian can identify most hypothyroid dogs (and even the much rarer hypothyroid cat) with a one to three tests,  Free T4, T3, and, when required, a TSH stimulation test.

However, a few cases that your veterinarian sees have all the common symptoms of hypothyroidism – but they can’t seem to be confirmed hypothyroid with those first three tests alone. Other dogs are checked for the presence of anti-thyroid antibodies because they haven’t responded satisfactorily to a standard veterinary dose of thyroid medication.

In some of those dogs – particularly golden retrievers, Shetland and Old English sheepdogs, and doberman pinschers – anti-thyroid antibodies that destroy the dog’s own thyroid hormones as well as thyroid supplements are to blame. The anti-thyroid antibody test can help identify those dogs. 

In another situation, potential breeding dogs can be screened for genetic susceptibility to this form of hypothyroidism. Elevated anti-thyroid antibody often appears in dogs before actual disease becomes evident and before T3 and T4 levels become subnormal. Hypothyroidism is extremely rare in cats so I can not tell you much about the test’s use in felines.

Complementary Tests:

Most likely, a complete thyroid panel would have been run before an anti-thyroid antibody test was suggested. An exception would be dogs being screened for a tendency toward hypothyroidism.

DxMe

You are on the Vetspace animal health website

Visiting the products that you see displayed on this website help pay the cost of keeping these articles on the Internet.