Keynote: Use of Deslorelin Implants to Schedule Canine Breeding Activity: A Study on 442 Bitches

Deslorelin implants were previously reported as a valuable alternative for fertile estrus induction in adult bitches (1,2). Since bitches might cycle anytime throughout the year whereas puppies can be more easily sold at certain periods, GnRH implants could be proposed as a tool to schedule the breeding activity in kennels. The aim of this study was to evaluate, in a large kennel breeding various breeds, the influence of such induction protocols on fertility. 442 bitches from one kennel were included. 16 breeds were represented (345 bitches 25kg). Among the 442 dogs, 71 bitches were treated: half of a deslorelin implant (Suprelorin®4.7mg, Virbac, Carros, France) was subcutaneously inserted in the umbilical region at least 5 months after natural estrus. The other bitches (n=371) mated on spontaneous estrus during the same period of time were included as control dogs. Time of ovulation was determined either by vaginal resistivity measurement (Ovulstart®, Nature et complements, France) (3) or by quantitative progesterone assay (MiniVidas®, Rhône-Mérieux, France): ovulation was considered when blood progesterone concentration reached 7ng/mL. Implants were removed on the day of ovulation (2) or 20 days post-administration if ovulation did not occur.  [...]