Dystocia and Foal Survival

Decisions made in the event of a dystocia may dictate the future health and survival of the foal. Rossdale and Ricketts (1974) reported that dystocia occurs in approximately 4% of Thoroughbred foalings. Abnormal orientation of the fetus in the birth canal (i.e. postural abnormalities) has been noted to be the most common cause of dystocia in the horse (Rossdale and Ricketts 1974; Roberts 1986). Ginther and Williams (1996) reported an overall dystocia rate of 11.2% for 517 spontaneous parturitions on a group of 8 equine breeding farms.

Early recognition and intervention during a dystocia may be required to save the life of the foal, save the life of the mare, and to preserve future fertility of the mare. A retrospective study of dystocias at a referral hospital indicated that each 10 min increase in the duration of stage II labour beyond 30 min was associated with a 10% increase in the existing risk of a foal being born dead and a 16% increase in risk of the foal not surviving to discharge from the hospital (Norton et al. 2007). Byron et al. (2002) further noted that the interval from rupture of the chorioallantoic membrane to delivery of the fetus was 13.6 min shorter for foals that were born alive and survived to discharge than for foals born dead or that did not survive to discharge. Together, these studies reinforce the concept that early accurate detection of a foaling problem and early effective intervention is critical to foal health and survival. [...]