Equine dystocia in Sweden (2006-2022): a retrospective analysis of mare and foal survival

Dystocia is an uncommon but potentially life-threatening complication of equine parturition. Due to early separation of the chorioallantois during the expulsive stage, fetal oxygen supply rapidly becomes compromised, making dystocia a time-critical emergency for both mare and foal. Objectives: To describe obstetrical interventions performed at equine referral hospitals, evaluate mare and foal survival, and identify factors associated with survival outcomes in a Swedish population where geographic distances may influence access to specialized veterinary care.

Medical records from three equine referral hospitals in central Sweden were reviewed for dystocia cases presented between January 2006 and December 2022. Data collected included dystocia causes, obstetrical interventions, dystocia duration, prior veterinary intervention, and survival outcomes for mares and foals.

A total of 138 dystocia cases were included. Fetal causes of dystocia predominated (114/138), with malposition being most common (106/138). Controlled vaginal delivery was the most frequently performed intervention (33.3%, 46/138). Of 140 foals delivered, 17.1% were born alive and 12.1% survived hospital discharge. Foal survival was not different among delivery methods (p = 0.145). However, survival was significantly associated with shorter dystocia duration (p < 0.01) and was higher when no obstetrical intervention had been attempted prior to referral (p = 0.0436). Among mares, 23.2% did not survive to hospital discharge, most commonly due to endotoxemia or sepsis.

Duration of dystocia prior to hospital admission was a key factor associated with neonatal survival, highlighting the importance of early recognition of dystocia, close monitoring of mares approaching foaling, and prompt referral to specialized equine hospitals.