Pregnancy rate and litter size of English Bulldog bitches inseminated with fresh semen

The present study aimed to evaluate the estrous cycle of Bulldog bitches using vaginal cytology, and to inseminate these with fresh semen, leading to the determination of pregnancy rate and the size of the litter. Sixteen (16) English Bulldog breed bitches were used, all with good reproductive history and proved fertility, age ranging from 1.5 to 6 years. Associated with the proestrus detection (external signs: vulva edema and a blood-stained discharge) was performed the vaginal cytology in order to determine the oestrus moment, as well was observed the female behavior of male acceptance. The artificial inseminations (AI) started when the vaginal cytology showed 90% of superficial cells, then repeated every 48h until the vaginal cytology change to metaestrous (increasing the nucleated cell counting) and/or the bitch stop to accept the dog mating. Digital manipulation was used to perform the semen collection, all male breeders underwent a previous seminal examination being selected for use only those ejaculates with more than 70% of total motility, vigor 3 and, at least, 200x106 of spermatozoa. The AI was performed using the intravaginal technique with all the collected ejaculate. The gestation confirmation were made by transabdominal ultrasonography between 25 and 30 days after the last AI, the ultrasonographic evaluation after that was carried out periodically in order to determine the best moment to perform the c-section. The vaginal cytology evaluation, associated with the comportamental changes in the bitch was efficient to detect the estrous onset in 100% of the bitches. Fourteen out of the 16 bitches inseminated got pregnant (87.5%). The litters had a mean number of 5.6 puppies, of those 53.1% (42/79) were male and 46.8% (37/79) were female. In conclusion, AI with fresh semen and whole ejaculate lead to good results in terms of fertility and a large litter size in English Bulldog bitches under these experimental conditions.