An Overview of Developmental Disorders Leading to Dystocia in Cattle.

Dystocia due to developmental disorders causing foetal malformation is a significant challenge in bovine obstetrics, often resulting in severe birth complications. This narrative review provides an updated overview of the most common congenital syndromes associated with dystocia in cattle, emphasising both their clinical implications and underlying causes. Congenital disorders such as schistosoma reflexum, perosomus elumbis, arthrogryposis, hydrocephalus, anasarca and embryonic duplication are reviewed in detail, along with their impact on the course of calving. While the management of dystocia due to foetal malformations has remained relatively constant over time-mainly involving assisted delivery, foetotomy or caesarean section-our understanding of their aetiologies has advanced considerably. In addition to environmental factors, such as viral infections during gestation, genetic causes may also be implicated. Genetic aetiologies, including dominant de novo mutations and recessively inherited alleles, such as single nucleotide variants, larger structural variants or aneuploidies, have been identified as the cause of some of these congenital defects. This review provides a comprehensive resource on dystocia due to developmental disorders, offering veterinarians updated knowledge to guide clinical decision making and improve outcomes for both the dam and the calf.