Evaluation of two sedation protocols for use before diagnostic intra-articular anaesthesia in lame dogs.

To assess the influence of two sedation protocols on the degree of lameness in dogs. Fifty lame dogs were allocated to one of two sedation protocols. Group ACPM (acepromazine + methadone; n=25) was sedated with acepromazine and methadone. Group MED (medetomidine antagonised with atipamezole; n=25) was sedated with medetomidine and reversed with atipamezole. Each dog was evaluated for lameness before and after sedation using videotapes. Four experienced clinicians allocated global lameness scores before and after sedation to each dog using a numerical rating scale. In 80% of the dogs in group ACPM and in 72% in group MED lameness was not affected by the sedation. In 12% of the dogs in group ACPM and 20% of the dogs in group MED the observers noticed an increase of lameness of 1 or 2 degrees on a scale of 0 to 10. In 8% of the dogs in both groups lameness decreased with 1 degree. A possible diagnostic test for investigation of obscure lameness is intra-articular anaesthesia. Sedation is necessary to allow intra-articular injection. This study provided evidence that the effect of sedation with the proposed protocols on the degree of lameness is negligible.