Hypothyroidism, Canine - contd.
Clinical signs vary and are gradual in onset, but typically include: lethargy, listlessness, or drowsiness; mental depression; exercise intolerance; weight gain; personality change; seeking out warm places; and infertility in some breeding animals. Additional symptoms include hair loss on the tail and along the trunk or body, resulting in a "rat tail" appearance; dry or oily skin associated with hyperpigmentation, or darkened skin; and thickening of the skin. The cardiovascular system can develop bradycardia, which is a decreased heart rate. Neuromuscular signs may include seizures; ataxia or stumbling; circling; knuckling or dragging the feet that results in the dorsal, or top, part of the nails being worn down; and forelimb lameness.
