Factors influencing English Bulldog bitch fertility after surgical uterine deposition of fresh semen

The aim of this study was to evaluate the effect of body weight, oxytocin deposition in the uterus at artificial insemination (AI), vaginal cytology, serum progesterone (P4) concentration at AI, semen volume and total sperm cells per AI on whelping rate and litter size of English Bulldogs bitches following intrauterine surgical semen deposition. Seventy-eight English Bulldog bitches were artificially inseminated via semen infusion (number of sperm cells inseminated 300–2500 × 106) at the uterine body with fresh semen without extender and under general anesthesia. Whelping rate was greater (P 23 kg than bitches with 4 mL semen volume maximize whelping rates in this breed of dogs. •Of 78 English Bulldog bitches that were surgically inseminated with fresh semen, 56 (71.8%) gave birth.•Mean litter size was 3.04 ± 1.76 pups with a large variation among bitches.•Pyometra in uterine horns was detected in 7.1% of the bitches and this was associated with a single puppy litter.•Whelping rate obtained with bitches weighing 23 kg (83.9%).•Whelping rates with intrauterine insemination are maximized with the application of ≥4 mL of fresh semen.