Description of the Type of Chemical Restraint Used by French Veterinarians to Perform Hip Dysplasia Screening Radiographs. A Retrospective Study Based on 3302 Radiographs

The objective of this study was to investigate the type of chemical restraint used by French practitioners to perform official hip screening radiographs, to determine the proportion of dogs under general anesthesia versus dogs under sedation, and to search for a difference in hip dysplasia (HD) prevalence between the two groups. From September 2005 to August 2008, 3302 conventional ventrodorsal hip extended radiographs sent for official scoring to the same panellist were selected because information related to the type of chemical restraint had been provided. There were 2825 dogs under general anesthesia and 477 were sedated. Chemical restraint used by French veterinarians to perform HD screening radiographs is mainly based on general intra-venous anesthesia with an alpha2 agonist associated with ketamine. A single injection of alpha2 agonist is also mostly used for dogs which are radiographed while under sedation. A very low (1.7%) difference in HD prevalence was noted between the anesthetized and the sedated group. Except for acepromazine, which has been demonstrated to provide insufficient muscle relaxation to show evidence of hip laxity, the protocols seem acceptable as regards the Federation Cynologique Internationale requirements for HD screening.