Diagnosis

Based on the combination of history, physical exam, radiographic and clinical pathology results we think the foal has osteomyelitis of the growth plate proximal to the metatarsal-phylangeal joint of the right rear limb.  The aspirate of the lame joint revealed the presence of Klebsiella(gram negative)  possibly originating from traumatic or hematogenous routes. The increased protein found and mononuclear cells in the joint are indicative of joint sepsis, which is secondary to the osteomyelitis  spreading to the joint. Radiographs reveal bone lysis and a widened growth plate, both of which are lesions consistent with osteomyelitis.