Management of the Pregnant Mare

Producing a healthy foal starts with good management of the pregnant broodmare. Follow these steps to help ensure a positive outcome

1. Ultrasound all mares at 14 to 16 and 35 days of pregnancy to minimize the chance of twin pregnancy. Mares are not capable of producing normal, healthy twins. Most mares pregnant with twins will lose the pregnancy at 5 to 10 months. These mares are at risk of difficult foaling, retained placenta and laminitis. Sometimes mares will continue pregnancy and deliver small and weak foals that require intensive and expensive care. Ultrasound at 14 to 16 days after breeding is useful to detect and correct twin pregnancies. In almost all cases of twins detected and treated early, the mare will go on to have a normal pregnancy and deliver a healthy foal.

2. For mares with poor perineal conformation, ensure a Caslicks procedure is performed early in pregnancy. The Caslicks procedure will prevent manure from entering the reproductive tract, where it causes infection and abortion. Remember to have the Caslicks removed before foaling.   

3. Protect mares from infectious abortion caused by equine herpesvirus 1 (Rhino). After twins, rhino is the most common cause of abortion in mares between 5 and 10 months of pregnancy. Rhino infection can also cause seemingly normal newborn foals to die soon after birth. Vaccination at five, seven and nine months of pregnancy reduces risk, but good management is essential to really protect against this disease. For more information, see Rhino under equine vaccinations.

4. Vaccinate all broodmares four to six weeks before foaling against tetanus, West Nile virus and influenza. Vaccinating at this time is safe, ensures the mare remains healthy and stimulates her to produce colostrum with high levels of protection against these diseases. Foals that ingest and absorb the colostrum of a properly vaccinated mare do not require vaccination until nine months of age.

5. Deworm mares every eight weeks throughout pregnancy and on the day of foaling. This will prevent the foal from ingesting harmful parasites from milk and manure in the first weeks of life.

6. Ensure proper nutrition for broodmares. Mares that are over fat or very thin have more difficulty during pregnancy and at foaling. Correct intake of minerals and protein during pregnancy helps protect foals from developmental problems later in life.

Back to top