It helps to know if the mare just retired from an athletic career, with possible athletic injuries, or drug therapy such as anabolic steroids that might hinder reproductive performance. Past breeding and reproductive records are helpful such as knowledge of the mare’s heat cycle patterns, length of anestrus and transitional heats when coming out of anestrus, number of previous foals, how recently she had her last foal, gestation length, whether births have been normal or difficult, any foaling complications, retained placenta, and so on. An accurate history can disclose factors that might directly or indirectly have an influence on her future reproductive abilities.

“Sometimes owners don’t realize how valuable these records are. If they say their mare hasn’t conceived and give me no other information, then I must go through the whole route of looking for the problem. If they can elaborate and tell me she hasn’t had a heat for 8 months I don’t have to spend time looking at all the other things; I can focus on a hormonal problem like a possible granulosa cell tumor in the ovary. The more history I get, the less money the owner will have to spend,” explains Thelfall. A thorough history helps the veterinarian see where to focus with diagnostic tests, rather than doing all of the tests on every mare.
Records (or evidence) of previous reproductive surgery such as Caslick’s repair or correction of abnormal perineal conformation can indicate there was need for correction of a problem that might compromise conception or pregnancy. Information about any prior uterine infection and previous treatment can also be important.
Earlier data will be helpful when compared with the results of subsequent examinations to determine whether the mare’s condition has improved, remained the same, or worsened. Evidence of early embryonic death or early pregnancy loss during previous pregnancies (the mare checked in foal early on and later was open) is also important. Accurate records can help determine the cause for loss of pregnancy, when combined with examination of the mare’s reproductive tract and diagnostic laboratory findings. Good records, in conjunction with various aspects of the examination, will give the veterinarian a picture of what’s going on, and how much time might be needed to correct it.
“We like to do breeding soundness exams in the fall, to give us more time to get a problem corrected. We know the longer that inflammation is in the uterus, the more likely we’ll have scar tissue present. If she was bred this breeding season and didn’t conceive, and we see her in the fall, we can do all the workups and find out what’s wrong. We can treat her now. It is always a good idea to get a mare ready for early breeding,” he says. This gives you more time early in the breeding season to finish correcting any problem that might otherwise interfere with pregnancy.
“By doing all this, you are preparing for the next breeding season, instead of going into it with a mare that’s not fertile and you don’t know what’s wrong. You might breed her three times and by the time you find out what’s wrong, it may be too late to breed her this year,” says Threlfall.
Fall is a practical time to check mares and get ahead of the curve if complications arise. “You can get these things done and have them ready to go for next year,” he sums up.
Heather Smith Thomas has raised and trained horses for 50 years and has been writing about them nearly that long, selling more than 9000 stories and articles and publishing 20 books. She and her husband raise beef cattle and horses on their ranch near Salmon, Idaho.