Among 18 758 intact female dogs seen in UK veterinary clinics, 701 dystocia cases were identified, with a 3.7% prevalence rate of emergent dystocia cases in the overall population.
Dystocia was most common in French bulldogs, Boston terriers, pugs, and Chihuahuas. Brachycephalic breeds represented 3 of the 4 breeds at the highest risk for dystocia. Most (94%) affected dogs were purebred bitches. Purebred dogs were found to be 3.4 times more likely to develop dystocia as compared with crossbreed bitches. Identification of at-risk breeds may help veterinary professionals inform breeders and owners about responsible breeding practices and reduce the incidence of dystocia in high-risk breeds.
Body weight also had an impact on risk, with dogs that weighed less than 22 lb or more than 88.2 lb at higher risk as compared with dogs that weighed 44.1 lb to 66 lb. Bitches between 3 and 5.9 years of age were 3.1 times more likely to experience dystocia as compared with younger intact female dogs.