Breeding Soundness Exams for Horses

As humans, we naturally think that we can improve on what Mother Nature has given each species, including horses – or should I say especially horses.  In some cases, we may have succeeded.  Just look at some of the great accomplishments of famous horses in just about every breed.  In fact, the number of different breeds we have today may well have resulted from improvement efforts.  Enough on that – here are some reasons why a breeding soundness exam is important for both the stallion and the mare prior to breeding.  Since the breeding season for horses will be here before long (starts in May and runs through September) it’s time to start preparing for breeding – including getting a breeding soundness exam scheduled.

There are several reasons to want to perform this exam on both the mare and the stallion.  The main reason is to be as sure as possible that a foal will result from the stud and mare getting together.  A lot of things can affect that end result, including condition; location of bacterial colonies, structural defects, and the list goes on.  I’ll address a few of the things that are examined without getting into too much detail and give a couple of sources for folks who want all the information.

For the stallion, it is a good idea to start with history.  Check to see what his performance was the previous breeding season.  If it was OK, then move on to the next item on the checklist.  If low (lower than expected foals born) then some time spent researching why that happened would be in order, looking for such things as reproductive history and management of both the stallion and the mare (breeding, feeding, and housing).  The stallion should have positive identification – make sure you are getting what you are paying for – and should be free of Equine Infectious Anemia, Equine Viral Arteritis, and Contagious Equine Metritis.  Conformation should be checked, including lameness, vision, inherited defects, Parrot Mouth, and chryptorchidism, to name a few of the items checked during an exam.   Genitalia are examined either physically or though use of ultrasound equipment.

Semen is collected and examined for pH, sperm motility over time, bacterial cultures, and the number of abnormal sperm cells.   Semen collection should be conducted by people who are trained or have experience.  A lot of bad things can happen during the collection process, including getting kicked. All this is pretty important and helps ensure that the stallion is physically able to breed and have a high success rate.  For more detailed information on breeding soundness exams of stallions, visit the LSU Vet School page titled Stallion Breeding Soundness Examination.  (If you get a message that Adobe Reader is blocked for this web site, click OK to trust the site.)

For the mare, many of the same recommended steps are taken in a breeding soundness exam.  Identification is verified and her reproductive and medical history is reviewed.  She gets a complete general and physical examination along with a detailed examination of her reproductive organs.

The physical exam includes checking temperature, heart rate, respiratory rate, teeth, eyes, mucous membranes, superficial lymph nodes, and checks for other physical abnormalities. Hereditary defects such as Parrot Mouth and limb abnormalities should be noted, along with anything that may interfere with the mare’s reproductive performance.

The reproductive exam includes a perineal inspection, rectal palpation and ultrasonography, a speculum examination of the vagina, a uterine culture and cytology to rule out a uterine infection, and a uterine biopsy.  For more detailed information on the BSE for mares, read the article written by Dr. Troedsson of the University of Florida, Breeding Soundness Examination of the Mare.

Horses have been able to reproduce on their own for a long, long time, so maybe some folks will ask why we don’t just let nature take its course?  Well, nature does take its course.  We just want to try and improve the odds a bit by making sure that all the parts are in the right place and not being influenced by some other outside force, like a uterine infection or a sore hoof.  If we are going to take time effort and expense to try and get a healthy foal, the least we can do is try to make sure all the conditions are right for the magic of a new foal to happen.