Risk Factors associated with the Incidence of Foal Mortality in a Pregnant Mare Urine Herd
The purpose of this study was to determine the incidence of neonatal mortality in a large pregnant mare urine (PMU) herd and determine what risk factors were involved in foal mortality. For a 6 week period between April 18, 1994 and May 31, 1994, 334 foals were born, of which 74 died before reaching 10 days of age, giving an overall mortality of 22% for this period. Seventy four percent of the foal deaths occurred within 48 hours of parturition. The major causes of foal mortality included starvation/exposure 27%, septicemia 26%, and dystocia 20%. Weekly incidence varied significantly ranging from 67% for week 1 to 14% for week 5 (p< 0.01). Other risk factors which were associated with foal death included failure of passive transfer (p< 0.0001), poor mothering ability (p< 0.0001), the presence of dystocia (p< 0.0001), low birth weight (p< 0.05), lack of rainfall (p< 0.01), and low temperatures (p< 0.1). The effect of sire, mare age, mare body condition score and foal sex were not significant risk factors for foal survival (p> 0.1). Further studies are required to determine if changing management procedures will be effective in reducing the incidence of neonatal foal mortality in PMU herds.
Master of Science (M.Sc.)
Western College of Veterinary Medicine
Department of Herd Medicine and Theriogenology