Because thyroid hormones have actions throughout the body, signs of hypothryoidism can be highly variable. Hypothryoid dogs can have any of these signs or a combination of signs. Other common signs are weight gain, mental dullness, lack of interest in activities, intolerance to cold, slow heart rate, and infertility. There are only a few abnormalities on blood tests from dogs with hypothyroidism. Elevation in cholesterol, however, is very common.
Some hypothyroid dogs have a mild anemia.
In two weeks, I'll finish the discussion of hypothyroidism by discussing the diagnosis and treatment.