The key to having a healthy foal begins with appropriate mare care. Great nutritional demands are placed on the mare during the last trimester. High quality hay and grain should be fed to ensure adequate nutrition and proper foal development. Too much of a good thing can be bad, however.
Obese mares can have difficulty fouling.
Pregnant mares should be de-wormed at least three months with a wormer labeled safe for use during pregnancy. An additional worming two or three days after foaling reduces transmission of parasites through milk. Vaccinating the mare during pregnancy helps guard against abortions and improves the quality of the colostrum. Thirty days before foaling the mare should be vaccinated against Eastern and Western Encephalomyelitis, tetanus, and Influenza. At this time, the mare should be housed in a clean, dry stall out of the wind.