Aetiology and pathogenesis of congenital torticollis and head scoliosis in the equine foetus.

The article discusses the study conducted on 214 cases of severe foal birth complications in mares, including cases of deviation of the head and neck. It concludes that the complications resulted from unfavorable conditions in the uterine environment, not genetic factors.

Research Findings

• The study examined 214 cases of severe dystocia – a term used for difficult or abnormal childbirth – in mares. Of these, 141 (or 66%) were Draught horses.
• In these cases, the cause of dystocia was observed to be a deviation of the head and neck, with or without torticollis (a condition where the head becomes persistently turned to one side), malformed head, and limbs.

Study Observations and Hypothesis

• The researchers did not find any evidence to suggest a genetic lethal factor causing these syndromes. Torticollis was often found in conjunction with scoliosis of the head and malformation of limbs, indicating that they shared a common cause and pathogenesis.
• These malformations were associated with an increased occurrence of caudal (pertaining to the tail) and transverse presentations. This is considered proof to support the theory that during the second half of pregnancy, the narrow tip of the uterine horns does not offer sufficient space for the cranial half of the foetus to develop appropriately.

Conclusion and Further Evidence

• The recovery rate of the born foals further supported the researchers’ findings. Foals suffering from severe malformations born via caesarian section exhibited rapid and total anatomical and functional recovery. This suggests that contrary to potential assumptions, these malformations weren’t genetically determined, but rather resulted from unfavorable conditions inside the uterus.
• Additional research may be necessary to understand how varying uterine conditions can best be managed to decrease the likelihood of foal malformation in future pregnancies.