Suitability of four injectable anesthetic protocols for percutaneous synovial fluid aspiration in healthy swine under field conditions and assessment of lameness seven days post procedure

Abstract

Objective: To compare the suitability of four anesthetic protocols for ante-mortem percutaneous synovial fluid aspiration from healthy swine in field conditions. A supplemental objective was to assess the iatrogenic impact of ante-mortem joint sampling by monitoring lameness and joint swelling after the procedure and assessing synovium histology at day seven post treatment. Materials and methods: Twenty-four finisher pigs (mean weight 86.1 kg ± 10.6) were each randomly allocated to receive one of four intramuscularly administered anesthetic protocols: telazol-ketamine-xylazine (TKX); telazol-ketamine-acepromazine (TKA); ketamine-acepromazine with lidocaine epidural (KAL); or telazol-acepromazine with lidocaine epidural (TAL). Synovial fluid was collected aseptically from one carpus and tarsus joint per anesthetized pig. The anesthetic protocols were evaluated in terms of successful general anesthesia, time to sternal recumbency and time to standing recovery, and protocol cost. Joint swelling and lameness assessments were completed on days two, four, and seven post sampling. On day seven, pigs were euthanized and synovium was collected from each sampled joint for histologic evaluation. Results: The TKX and TAL treatments were the only anesthetic combinations that provided an adequate anesthesia depth for fluid collection to occur. Mean (SD) time to sternal recumbency for TKX was 125 (26) minutes and for TAL was 198 (28) minutes. There was no evidence of post-aspiration infection in any sampled joints. Implications: The TKX treatment was the most effective anesthetic protocol for ante-mortem joint fluid collection. Ante-mortem joint fluid collection was not associated with significant joint tissue damage and can be a useful diagnostic tool for infectious arthritis.