title: Parturition, dystocia and foal survival: a retrospective study of 1047 births.
abstract: BACKGROUND
  An understanding of the normal events of foaling, causes of dystocia and clinical outcomes is important for equine practitioners.
  
  
  OBJECTIVE
  The goals of the present study were to: 1) evaluate factors that influence gestation length; 2) report duration of Stage II labour; 3) determine the frequency of dystocia and premature placental separation; and 4) determine the relationship between problems at foaling and foal survival.
  
  
  METHODS
  Foaling records of 1047 mare births were evaluated.
  
  
  RESULTS
  The average gestation length was 342.7 days [corrected] +/- 0.4 days, with no effect of mare age or breed observed. Mares carrying male fetuses had a longer gestation (P < or = 0.001) than mares carrying female fetuses. A majority (52.8%) of mares foaled at night between 2000 h and 0200 h when the facility was quiet. Dystocia occurred in 10.1% of all births and the incidence rate was higher in Thoroughbred mares than in Quarter Horse mares. The most common cause of dystocia was abnormalities of fetal posture. A delay in foal delivery beyond 40 min of Stage II of labour was associated with a significant increase in foal mortality. In addition, an increase in foal morbidity and mortality was noted when the interval from birth to standing or birth to nursing was prolonged.
  
  
  CONCLUSIONS
  Early detection and rapid appropriate intervention are critical to foal survival in an equine dystocia.
  
  
  CONCLUSIONS
  Equine veterinarians should counsel horse owners that early recognition of a foaling problem and rapid, appropriate intervention are critical to the survival of a foal.
authors.affiliation: Department of Clinical Sciences, Equine Reproduction Laboratory, Colorado State University, Fort Collins, USA. pmccue@colostate.edu
authors.forename: P M
authors.initials: PM
authors.lastname: McCue
authors.forename: R A
authors.initials: RA
authors.lastname: Ferris
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002940:Circadian Rhythm; D004420:Dystocia / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000209:etiology*; D006736:Horses; D008136:Longevity; D008297:Male; D036801:Parturition / Q000502:physiology*; D011247:Pregnancy; D012189:Retrospective Studies; D050497:Stillbirth