R OCKY S PRINGS
Free Spring Issue 2015
H ORSE N EWS Q UARTERLY Vol. 2 No. 2
April 2015
The Most Wonderful Time of the Year Story and photos by Cheryl L. Detamore, DVM For many people, “the most wonderful time of year” evokes the well-known classic Christmas song celebrating the holiday season. For horse lovers, it means foaling season! It’s been a long winter but an even longer wait for the muchanticipated debut of your new foal. As the arrival approaches, worry often replaces excitement. However, proper planning can alleviate the stress of uncertainty. Proper Health Care The average equine gestation period is 345 days, plus or minus two weeks, depending on the breed and climate in which the mare resides. Mares foaling in warmer climates or during warmer months tend to deliver early, although those due in colder months or climates are more likely to exceed their expected due date. Maiden mares, or first-time mothers, might deliver prematurely. Early in pregnancy, or at least 45 days before foaling, remove mares from fescue grass to prevent problems. Fescue toxicity in pregnant mare causes significant problems, including prolonged gestation, retained placenta, absence of milk and delivery of weak foals. Continue routine vaccinations based on your geographical recommendations. If your barn has several breeding females, heavy horse traffic or a history of abortion, vaccinate pregnant mares at five, seven and nine months of gestation for the abortogenic strain of equine herpes virus, or EHV-1, to protect against late-term abortions and birth defects. Don’t confuse this with immunization for rhinopneumonitis, or EHV-4, a different viral strain that causes respiratory and neurological disease in young and adult horses. Give all mares tetanus toxoid boosters six weeks before their due dates to protect them during and after delivery and to ensure that their colostrum contains adequate levels of antibodies to the disease. The organism that causes tetanus is actively secreted in horse manure and lives in the environment where horses are kept, making them extremely susceptible to the disease. Mares are particularly vulnerable at foaling time, especially in cases of prolonged labor, or when partially retained fetal membranes are allowed to contact the ground. Foals, meanwhile, are at risk of contracting tetanus through their navels.
You can safely treat mares for parasites throughout their pregnancies, and it’s recommended that you deworm pregnant mares six weeks before their expected due dates. This ensures that they’re in good condition at foaling and that their milk is free of parasites. Mares that have undergone Caslick’s procedures need special attention. In this minor surgical procedure, the upper portion of the vulva is sutured shut following breeding, allowing just enough space for the mare to urinate. It’s performed primarily in older mares with genital conformations that contribute to fecal contamination of their reproductive tracts. Without this procedure, many mares are unable to carry a pregnancy to term. In preparation for foaling, the veterinarian opens the vulva by cutting along the center where the tissue has been sewn together, while using local anesthesia. It’s also advisable to remove shoes, to prevent mares from injuring themselves during labor and from damaging their foals after delivery. Bare feet aren’t nearly as dangerous to delicate newborn flesh or as likely to cause fractures as those that are shod. Expectant mares should receive moderate exercise to maintain fitness, even in the last weeks of pregnancy. Daily exercise strengthens muscles, promotes circulation and prevents colic. Even though pregnancy and impending lactation increase nutritional demands, don’t allow mares to become sedentary and obese. Mares rarely suffer from obesity-related dystocia (difficult birth), but extra weight causes fatigue during delivery. Continued on page 8