Spontaneous Septic Arthritis of Canine Elbows: Twenty-One Cases.

OBJECTIVE

This study provides information on clinical features, diagnosis, treatment and associated risk factors of spontaneous septic elbow arthritis in the dog.

METHODS

Medical records between March 2007 and June 2015 were searched for cases of spontaneous septic elbow arthritis with a diagnosis based on clinical signs, arthrocentesis, cytological and microbiological analysis of elbow joint synovial fluid, radiography and outcome following treatment.

RESULTS

Twenty-one cases of septic arthritis were identified. Pre-existing osteoarthritis was present in 14/15 elbows for which diagnostic imaging was available. Although all cases had increased neutrophil count on synovial fluid cytology, culture was only positive in 12/21. Despite initial improvement in lameness scores (pre-treatment 9/10 [range: 1-10] versus post-treatment 3/10 [range: 1-5]), 11/12 had residual long-term lameness. Recurrence of infection was noted in 3/12 elbows for which long-term (>8 weeks) follow-up was available. There was an acute mortality rate of 2/21 associated with severe systemic sepsis.

CLINICAL SIGNIFICANCE: Septic arthritis, even in the absence of pyrexia, should be considered as a major differential diagnosis in middle aged, large breed dogs, with pre-existing elbow arthritis, that suffer an acute onset lameness, with elbow joint effusion and discomfort. Antibiotic therapy alone was effective for treatment with high initial response rates. Chronic lameness post-treatment was common, and a high rate of recurrence was seen with 3/12 dogs suffering more than one episode.