A prospective cohort study investigating the peri- and postoperative outcomes following ovariohysterectomy in bitches neutered prepubertally or post-pubertally

Abstract

The aim of this prospective cohort study was to investigate perioperative and postoperative outcomes for bitches that were neutered at different times in relation to puberty (rather than age). Three hundred and six Labrador and Golden Retriever crossbreed bitches were neutered before (prepubertal neuter [PPN], n = 155) or after puberty (Control, n = 151) by experienced veterinarians at one of four veterinary practices (VP1-4). Data were gathered from veterinarians at the time of neutering and from bitch caregivers for the 14-day period after neutering using purpose-designed questionnaires. PPN bitches had shorter surgery durations than Control bitches (OR = 0.877, 91% CI = 0.800 to 0.961, P = 0.015). Longer surgery durations were reported for bitches that had intraoperative complications (OR = 1.620, 91% CI = 1.397 to 1.879, P < 0.001). Shorter surgery durations were reported for VP1 compared to all other veterinary practices (OR = 1.189 to 1.534, P < 0.001). There was no difference in the number of PPN or Control bitches that had perioperative complications (PPN: 3.9%, n = 6; Control: 7.7%, n = 11) and no bitch had more than one perioperative complication reported. For the 14-day postoperative period, fewer PPN (1.3%, n = 2) compared to Control bitches (8.9%, n = 13) had wound discharge (Chi-square = 11.151, D.F = 1, P = 0.001) or showed inappetence (PPN: 2.9%, n = 4; Control: 17.3%, n = 19, Chi-square = 14.884, D.F. = 1, P < 0.001). There was no difference in the number of PPN and Control bitches that had redness or swelling of the wound (52 PPN, 48 Control), showed attention to the wound (6 PPN, 6 Control), required veterinary attention (25 PPN, 23 Control), or that showed any other unusual behaviours: discomfort (27 PPN, 16 Control), uncharacteristic irritability (2 PPN, 4 Control), or uncharacteristic licking or chewing of parts of the body (15 PPN, 6 Control). Bitches neutered at VP2-4 were more likely to have wound redness or swelling reported than those neutered at VP1 (OR = 3.109 to 4.076, P = 0.003). Future studies should consider the impact of veterinary practice on results. These results for peri and postoperative complications could suggest that prepubertal ovariohysterectomy may be a suitable option for neutering bitches. However, it is recommended that they be interpreted together with evidence relating to the impacts on other factors including behaviour and longer-term health in order to make fully informed decisions.