Dysfunction of the thyroid glands is common in dogs. In order to evaluate a patient’s thyroid function, we recommend the complete thyroid profile run by the Diagnostic Center at Michigan State College of Veterinary Medicine. The profile is run on a blood sample. Because it measures more that just the thyroid hormones, T3 and T4, the profile is very useful in differentiating true thyroid disease from conditions in which thyroid hormones are low because of non-thyroid disease. Many times the patient simply needs supplementation of the nutrients necessary to produce thyroid hormone. Simply treating the patient with thyroid hormone, overlooks the probability that the same nutrient deficiency may be effecting other areas of the patient’s body.