Sterile nodular panniculitis in five horses.

Sterile nodular panniculitis was diagnosed in 5 horses. Physical abnormalities were predominantly limited to cutaneous changes, consisting of multiple subcutaneous nodules that had a tendency to wax and wane over time and were commonly distributed over the trunk, neck, and proximal portion of the limbs. In each horse, the diagnosis was confirmed by excisional biopsy of a nodule and by exclusion of infective causes of panniculitis on the basis of negative culture results and special stain application to skin specimens. Treatment with immunosuppressive doses of glucocorticoids was curative in 1 horse, was required on a daily or alternate-day schedule in 2 others to keep the skin clear, and had no effect on the disease in the remaining 2 horses.