Bone involvement does not adversely affect outcome in calves with septic arthritis: Influence of treatment intensity

Septic arthritis is a common cause of lameness in calves and may be linked to radiographic signs of bone involvement, traditionally considered a poor prognostic factor. The aims of this retrospective study were to identify clinical and treatment-related factors that affected survival in calves with septic arthritis and to determine whether radiographic bone involvement adversely affected outcome.

Medical records of 46 calves diagnosed with septic arthritis were reviewed. Data collected included signalment, clinical findings, synovial fluid analysis, radiography, antimicrobial use, and treatment interventions. Calves were categorized as either euthanized at admission or treated in the hospital. Survival and prognostic factors were evaluated in treated calves (n = 29).

Radiographic bone involvement was identified in 22/29 treated calves (76%) and was not associated with decreased survival. Synovial fluid total protein and total nucleated cell count were numerically higher in calves with bone involvement but were not significantly associated with outcome. However, increasing treatment score, reflecting cumulative treatment intensity, was associated with improved survival (OR = 2.42; P = 0.014). In addition, repeated joint lavage was also associated with increased survival, whereas single interventions were not. Prior antimicrobial use on the farm did not significantly influence outcome.

We inferred that radiographic bone involvement should not be considered an automatic negative prognostic factor in calves with septic arthritis. However, the retrospective design and relatively small sample size of this study limited the strength of these conclusions. Instead, treatment intensity and a multimodal therapeutic approach appeared to have a more important role in determining outcome.