Dystocia: Factors affecting parturition in domestic animals

Abstract

Dystocia frequently develops when some physical obstacle or functional defect impedes the birth process. Due to the complex nature of the factors involved in the process of parturition, it may be difficult to distinguish between eutocia (normal delivery) and dystocia (difficult birth). It is essential to do so because the physiopathological effects of problematic labour often deteriorate the dam's fertility and, in severe cases, may cause her death as a result of damage to the genital apparatus and the secondary development of systemic infections. Also, if parturition is not successful, neonates could suffer prolonged episodes of hypoxia, which represents a leading cause of foetal death in cases of dystocia and, even when not fatal, can be a determining factor in neonatal survival. Given this, a better knowledge of the aetiology and physiopathology of dystocia will be keys to understanding this condition and adequate decision making in obstetrical practice and veterinary perinatology. Moreover, such knowledge will permit the timely identification of cases that require special attention and establishing actions to protect animal welfare and assess risks that, on occasion, will entail pharmacological control of eutocia or dystocia. Hence, this paper aims to review some of the most critical aspects involved in the process of difficult deliveries and their consequences for the dam and the foetuses of domestic animals.