Progress in foal survival rates
Newborn foals have a better chance of surviving today than ever before, but certain conditions and situations are still hard to overcome, according to a retrospective study from the University of Illinois.
“About 3 percent of foals born in the United States become quite sick during their first 30 days of life and need more extensive veterinary care, with a large percentage of those going to hospital for treatment,” says Pam Wilkins, DVM, PhD, who reviewed historical and recent studies to identify the factors that are most likely to affect or predict foal mortality rates. “In the 1980s we were looking at overall survival of 50 to 60 percent in very sick foals less than 30 days of age. Most of these sick foals now survive—about 80 percent.”
Difficult births, called dystocias, are not common but are true emergencies when they do occur, says Wilkins. About 10 percent of all births are dystocias, although the incidence rate is higher among Thorough-bred mares.
“Most dystocias are pretty easily correctable by good foaling managers or veterinarians on the farm, and both mares and foals do just fine,” says Wilkins. “It is the difficult ones—the ones that go on for more than 30 to 40 minutes from when the mare’s water breaks—that are the biggest problem. The chance of losing the foal increases about 15 to 16 percent for each 10-minute delay in getting the foal out after 30 to 40 minutes.” She adds that having a plan in place in case of dystocia—including transportation to a clinic—increases the odds of survival and is, therefore, a critical part of preparing for a foal’s arrival.
Foals born with orthopedic conditions are likely to survive today, but their athletic careers may be hampered, says Wilkins. “We can resolve many of the [contracted tendons] more easily now,” she explains. “Bone and joint infections are the biggest limiting factor, because both hold a worse prognosis for athletic career and survival.”
Wilkins also found that sepsis (body-wide infection) and prematurity still pose a significant threat of mortality, with survival rates improving from 30 percent decades ago to between 40 and 60 percent today.
Reference: “Prognostic indicators for survival and athletic outcome in critically ill neonatal foals,” Veterinary Clinics of North America: Equine Practice, December 2015
This article first appeared in EQUUS issue #461, March 2016.