The world is full of fertility specialists helping humans to get pregnant. But when horse owners run into difficulties with fertility issues, there are very few experts available.

Dr. Claire Plante, DVM, is an obstetric/gynecologic specialist and is the only veterinarian in Ontario certified by the Canadian Embryo Transfer Association for equine embryos. Dr. Plante and her partner, Dr. Daniel Jou, DVM, have focussed their energies and expertise on horse reproduction services for the past seven years at their laboratory/stable facility, Plante Veterinary Services, near Guelph, ON.

Horses can face all the same problems with fertility as people. Stallions can have low sperm counts; mares may have problems with ovulation, conception, and maintaining pregnancy. These issues can become a major roadblock for horse owners and breeders who want to continue a winning bloodline. Drs. Plante and Jou work with all breeds – Thoroughbred and Standardbred race horses, warmbloods, and even mustangs. “The goal is always the same,” explains Dr. Plante. “We want our clients’ horses to get pregnant and successfully deliver healthy foals! It sounds simple, but it is often very complicated. Breeding is very time-sensitive. Often, we have to monitor ovulation hour by hour.”

High-performance athletes are frequently bred by artificial insemination, which allows the mares’ owners to import frozen semen from the best stallions around the world. PVS offers collection services to stallion owners and can quarantine stallions to fulfill international export regulations. Their lab enables them to test, freeze, store, and safely thaw valuable horse semen at just the right moment for fertilization.

Some mares are sent to PVS for foaling if the owners are worried about a safe birth, and then will stay to be re-bred. Others have had problems getting pregnant and need to be assessed. In the case of very valuable mares, those that have to keep competing, or have proven to be unable to carry a foal to full term, they will be bred, then their fertilized embryo will be removed after seven or eight days and transplanted into a surrogate mare to gestate and deliver. Dr. Plante maintains a herd of about 15 surrogate mares just for this purpose. The surrogates normally go to the horse owner or breeder’s farm for the full term of the pregnancy and give birth there, or come back to PVS for foaling

Sometimes a very unusual request comes in, like one in late 2013. “A veterinary surgeon contacted us urgently. They had operated on a valuable and much-loved dressage horse who had injured her leg. The outcome was not promising,” Dr. Plante says. Everybody’s Darling, an 18-hand Oldenburg mare, had developed severe deterioration in the cartilage in her fetlock and vets advised that euthanasia was the only recourse. The heartbroken owners were informed that as the mare was cycling, Drs. Plante and Jou and their team may be able to perform AI and an embryo transplant and hopefully produce a foal from their beloved mare. So began an emotional journey that resulted in the birth in 2014 of a healthy filly by Jazz named Just Darling. “We kept the mare sedated and comfortable and were fortunate to have a successful breeding at the first try,” explains Dr. Plante. “We harvested the embryo before the mare had to be put down and the surrogate mare gave birth in September. The owner was very, very grateful that we were able to help her under such tragic circumstances.”

In another case, Shine of Light, a big Swedish Warmblood owned and ridden by Heather MacInnis and a proven winner in the grand prix ring, suffered a series of injuries that forced her into retirement. High hopes of producing a future champion were dashed when repeated attempts to breed “Luna” were devastatingly unsuccessful.

In 2014, Drs. Plante and Jou said, “We want to try again; there has to be a way.” This time the strategy was to get her pregnant and keep her pregnant long enough to transplant an embryo. Success came in June and an embryo, sired by Cabardino, was transplanted to a surrogate mare. That mare is now living in Heather’s show barn with Luna and is scheduled to foal in May this year.

“Claire and Daniel simply would not give up even when I was discouraged,” Heather commented. “I am grateful for their perseverance so that I may have a chance to keep Luna’s talent and bloodlines alive through her foal.”

Breeding of horses for sport or pleasure is a complex science. “But on a personal level, this job brings us so much joy and satisfaction,” Dr. Plante concludes. “Yes, we are scientists and veterinarians, but we are in the business of bringing new life into the world. That is why we love what we do!”


The neonatal intensive care unit at the University of Guelph’s Ontario Veterinary College is a haven to acutely ill foals. Veterinarian and OVC associate professor Luis Arroyo, DVSc, says the majority of the cases they see involve sepsis and equine neonatal maladjustment syndrome (dummy foal), in a variety of breeds. The ICU is designed with the intent of keeping stress levels for both mares and foals to a minimum. “We have a ward with big stalls and we try to keep mares and foals together as much as we can,” says Dr. Arroyo. “The stalls have [soft] partitions to try to maintain that bond between mare and foal, because if you separate the mares from the babies, a lot of times when you try to put them back, the mom will reject the baby. We also have many other stalls for babies alone, but we try to avoid that.” A 24/7 foal watch ensures that the little patients are monitored constantly.

The OVC facility is poised for a major facelift, says Dr. Arroyo. “We are in the midst of ramping up our ICU, including a dedicated wing of the hospital just for foal care during foal season that will be exclusively for mares and foals – no other patients – that will minimize traffic.” Ongoing research is also looking into better bed options for acutely sick foals “We’re looking at improving the nursing care, which would include providing more comfort through better bedding. We are testing things from mattresses to straw bedding. The whole purpose is to keep them dry and warm.”

In the past the ICU would see between 20-30 foals per year. “The caseload has changed dramatically; lately we will see only 10-15,” says Dr. Arroyo, who attributes this to several factors, including the demise of the Standardbred racing industry and more private practices that deal with foals.

One of their particularly challenging ICU cases recently involved an elite pacing mare and foal. The mare, Illusionist (“Lusi”) started showing signs of severe distress two weeks before her due date; examination revealed that her very large foal was literally tearing her apart inside. She was immediately shipped to the OVC, where she was diagnosed with a partial rupture in the pre-pubic tendon that supports the abdomen; a full rupture usually means euthanasia. A caesarean section was the only solution – except that premature foals often don’t survive.

Surgery was performed and “Albert” (like hurricanes, at the hospital foals are named alphabetically) was born. Foals are typically 90-100 lbs. at birth; Albert weighed a whopping 130 lbs. He quickly began to deteriorate, however, as his lungs weren’t fully mature and hypoxemia (low blood oxygen) resulted. Not able to urinate or defecate, on a ventilator with more than a dozen lines running into his body, and then developing an umbilical infection that required surgery, things looked grim. But a dedicated medical team saw him improve quickly and dramatically after that. He is now a healthy yearling, enjoying life on his home farm.

With ongoing research and better facilities being developed across the country, chances for foals who got off to a rocky start are becoming greatly improved. Concludes Dr. Arroyo, “Foals are always the most important – almost like children, they are the future.”

~ Susan Stafford-Pooley