Surgical treatment of osteomyelitis and formation of a sequestrum in the distal metaphysis of the humerus in an alpaca cria

Abstract

CASE HISTORY: An 8-week-old, 16-kg alpaca cria was presented with a 2-week history of acute onset of left forelimb lameness.

CLINICAL FINDINGS: The cria was weight-bearing but lame at the walk in the left forelimb. There was swelling, heat and pain on palpation of the soft tissues, extending from the mid-shaft of the humerus to the elbow. There was no evidence of a traumatic injury. Radiologically, there was evidence of osteomyelitis and a sequestrum involving the distal metaphysis of the humerus. The sequestrum was removed surgically. No bacteria were cultured from samples taken during surgery. After an initial improvement, the cria became acutely lame, and developed an abscess at the surgical site, which was drained. A pure growth of a strictly anaerobic, Gram-negative, non-spore-forming, pleomorphic, filamentous rod was cultured from fluid from the abscess. Further radiographs suggested a second sequestrum was present, and this was removed surgically. Apart from partial dehiscence of the wound, the cria recovered well, and was sound and without complications 18 months after surgery.

DIAGNOSIS: Osteomyelitis and formation of sequestra in the distal metaphysic of the left humerus.

CLINICAL RELEVANCE: There has only been one case of osteomyelitis and bone sequestration without evidence of trauma in alpaca crias reported in the literature. However, anecdotal reports by veterinary practitioners described similar cases of osteomyelitis and bone sequestration, usually affecting the long bones. Further investigation of osteomyelitis and bone sequestration in crias is needed, to define the incidence, determine the pathogenesis, and develop specific recommendations for prevention and treatment.

KEY WORDS:

• Alpaca
• cria
• osteomyelitis
• sequestrum
• orthopaedic
• bone
• infection