Dr. David Hartman from Whitesboro, Texas, indicates in Remuda Magazine that endometritis, or a uterine infection, is a common condition that causes infertility in many mares. He believes veterinarians and breeding farm personnel are involved either directly or indirectly as the cause of this problem. Rectal palpation is a common procedure that be performed on broodmares to examine the reproductive tract. If it is not performed correctly this procedure can contaminate the genital area, which can lead to infection. This infection can be introduced into the uterus at breeding, which can prevent pregnancy. To determine if a mare is infected, a uterine culture and a uterine cytology are important. Dr. Hartman indicates he believes cultures should be performed when the mare is in advanced heat as cultures taken at other times can be falsely negative. However, the cytology result is important to compare with the culture result because contamination can also cause false positive cultures.
Another method to increase pregnancy rate is to examine the mare’s ovaries, determine when she is going to ovulate, and give a drug to stimulate ovulation. This allows her to be bred only one time in most cases, which limits contamination. In cases in which the stallion has poor semen quality, insemination with a flexible pipette can be used to place the semen next to the ovulating ovary. If you have a problem with reproduction on your farm, consult your equine vet for recommendations.