An adult female African forest buffalo (Syncerus caffer nanus) of unknown age was presented with signs of recurrent hoof overgrowth, persistent anestrous, obesity, dull hair coat, and decreased activity level. Complete blood counts and serum biochemistry values were unremarkable. Decreased concentrations of total triiodothyronine and total thyroxine were noted compared with values for normal domestic cattle and a healthy African forest buffalo. Treatment with oral levothyroxine increased blood concentrations of total triiodothyronine and total thyroxine, and subsequent improvement in clinical signs included weight loss, hair regrowth, and reproductive cycling.