Improvement of the clinical signs of gait abnormality after treatment with levothyroxine in a horse with shivering and hypothyroidism.

An 11-year-old Hanoverian gelding used for jumping was evaluated for gait abnormalities and hoof problems in the hindlimbs. Clinical examinations revealed signs consistent with shivers. A thyroid gland enlargement was noticed, baseline serum thyroid hormone (TH) concentrations were low, and a low response to thyrotropin-releasing hormone administration was observed. Hypothyroidism was suspected. The horse was treated with levothyroxine for 1 year. TH concentrations returned to the normal range by week 4 of treatment. Thirty weeks after the initiation of levothyroxine therapy, the gait abnormality improved. Our findings suggest that the assessment of thyroid status and especially of the subclinical thyroid gland disorders in horses affected with shivering, as well as evaluation of the effects of levothyroxine on the improvement of clinical signs could be promising in establishing the aetiopathogenesis and/or treatment of shivering in horses.