Cutaneous and tendon sheath mastocytomas with eosinophilic joint and tendon sheath effusions in a horse.

摘要

A 4.5-year-old Quarter Horse gelding was referred for evaluation of a swollen right hind leg of 3 weeks duration, which had occurred after exercise. Lameness was not observed and cold hydrotherapy had resulted in little improvement. Two weeks before presentation, the gelding developed a swelling over the left zygomatic arch for which a tentative diagnosis of abscessation was made. However, the lesion was unresponsive to antibiotics, became pruritic, ulcerated, and exuded serosanguinous fluid. Two days before presentation, dexamethasone powdera was prescribed to treat the leg swelling. On the day of presentation, the gelding also developed a swelling overlying the xiphoid process and a swelling on the right lateral abdomen.