When trotting stallion Windsong’s Legacy died at age seven in 2008, Dr. Spears —as breeder of the great racehorse—retained breeding rights to the deceased stallion via his shareholder status.

“I phoned a major consignor at the upcoming Harrisburg Sale that year and let them know I was looking for a mare that would be compatible with Windsong’s Legacy,” Dr. Spears explained. “The consignor had a mare they thought would mesh well with the stallion. She had been a good race mare with acceptable genetics and credentials, and had been both ultra-sounded and palpated prior to sale. The report that came with her stated she was ‘sound and suitable for breeding,’ which is pretty standard in the breeding circles.”

After purchasing the mare, Dr. Spears shipped her to Perretti Farm in New Jersey where Windsong’s Legacy’s frozen semen and an artificial insemination procedure awaited her. Dr. Spears—a retired physician—employed the services of veterinarian Dr. David Meirs II to oversee the process.

“David called me and said he had palpated the mare and felt something was amiss, and he wanted to get a second opinion,” Dr. Spears offered. “I said fine. As it turns out, David was the hero in this scenario for eventually finding the marble.”

Meirs procured the services of a fellow veterinarian for the second opinion and together the pair discovered a marble—yes, a glass marble similar to what children play with—that had been placed in the mare’s uterus.

“This mare had changed hands a number of times, and so we don’t really know who was responsible for the initial placement of the marble inside her,” Dr Spears said. “And it’s also possible that if the ultra-sound was taken at an odd angle, the marble might not have shown up on the pre-purchase exam.

“This was a new one to me,” Dr. Spears continued. “And when thinking in terms of the sales company, it places a whole new burden on us. The question thus becomes, if you sell a mare at auction for breeding purposes, with no knowledge that she has a marble in her uterus where does that leave the sales company, the consignor, and the buyer?”

Dr. Spears does indeed, raise some poignant questions, and has every reason to be concerned. During the Standardbred Horse Sale at Harrisburg, held annually each November, Dr. Spears heads a team that transitions through a yearling sale to a mixed sale in a matter of hours.

“On Wednesday night of the Harrisburg sale, my whole sales consignment turns over from the yearlings to the open horses—which includes broodmares, weanlings, and racehorses,” Dr. Spears said. “It’s pandemonium in there. I hire extra, creditable veterinarians to come in and just palpate mares from late night until the next morning. It would be physically impossible for us to ultra-sound every broodmare that goes through the Harrisburg sale. There’s only so much that we—the sales company—can do. I think ultimately, the responsibility has to lie with the consignor.”

Dr. Tony Petrowitz, DVM, a practicing veterinarian servicing the sister harness racing tracks of Maywood and Balmoral, said he believes the responsibility lies with whoever performed the pre-sale, ultra-sound exam.

“Whoever ultra-sounded and palpated, and didn’t detect the marble, then writes the mare a clean bill of health to be sold as a broodmare is responsible,” stated Dr. Petrowitz. “If the buyer purchases a mare for breeding purposes, finds out she has a marble in her uterus and then goes back to the seller, that consignor is then going to go back to the veterinarian who performed the ultra-sound. That veterinarian is the person subject to liability since he’s the person who failed to detect the marble in his pre-sale exam.

“If you put an inter-uterine device into a mare, there’s always a chance that something may go wrong,” Petrowitz stressed. “In my opinion, a mare that’s been marbled should have it noted on her papers, and then there’s no chance of a buyer or a consignor, or a sales company being surprised. It’s right up front. Everything else is noted on a horse’s papers—Coggins, EHV-1 vaccinations, nerving, and whether a horse has been gelded or spayed. Noting this on the papers would avoid further confusion in the future for anyone buying, selling or claiming horses.”

According to Dr. Pete Sherrin, DVM, of Lexington’s Rood & Riddle veterinary practice, though marbling has been around for many years, the way it works continues to puzzle veterinarians and breeders alike.

“Nobody’s really sure why it quite works the way it does,” said Dr. Sherrin, an eight-year member of the Rood & Riddle staff and Board Certified Reproductive specialist. “Dr. Gary Nie—the veterinarian who performed the original study* on marbling in mares in 2001—found there to be no long term, detrimental effects on a broodmare’s reproductive system. His report found that in 60 to 65% of the mares, placing a marble in their uterus kept them from coming out of heat for about three months. After that, they began to cycle normally again.

“This procedure is mainly found in show horses,” Dr. Sherrin added. “The racehorse people are much more likely to use Regu-Mate® (the synthetic progestin Altrenogest). It has a higher efficacy rate (about 95%) and the cost isn’t as much an issue in racehorse circles, as it tends to be with show horses.”

Dr. Petrowitz agrees with Dr. Sherrin, and presents another reason some trainers may choose a marble over a medication.

“First, marbling defers the cost of Regu-Mate®,” Dr. Petrowitz noted. “But another reason to use a marble over medication would be because of the safety issues involved in the handling of Regu-Mate® on a daily basis. There are a plethora of warnings on the Regu-Mate® label about handling—especially by women of child-bearing years—and that fact alone could deter some trainers from using it, based on the possible liability factor.”

“’Marbling’ just isn’t a practice that a lot of people in the racehorse industry are familiar with,” acknowledged Bob Boni of Northwood Bloodstock Agency. “At the sales, mares are only palpated, and then issued a statement that says they are ‘sound and normal for mating.’ Ultra-sounding is not performed—it would be impractical to ultra-sound every mare.”

“At both Standardbred and Thoroughbred sales, palpation is the norm,” Dr. Sherrin agreed. “It’s possible that a veterinarian might miss finding a marble if an older mare had a saggy uterus, or in the case of some of the younger mares, in those who might be particularly difficult to work on.”

For those trainers who do choose to ‘marble’ their race mares, Dr. Sherrin offers words of caution and common sense advice.
“The only potential complication can arise when a marble is of low quality or has been in the mare’s uterus too long,” Dr. Sherrin stressed. “The marble can disintegrate and will break into pieces, resulting in glass fragments in the uterus. It’s not a good situation for the mare.”

“It’s important, if you’re going to place a marble in a mare, to get the proper size (35 mm) and a high-quality marble that is plain and clear. Anything smaller than 35 mm will not stay in position and be expelled. Also, colored or speckled marbles tend to be of low quality and are more likely to break into pieces. A solid, clear marble of the proper size is what you want to use to ensure the safety of the mare and her reproductive organs.”

Interestingly enough, uterine marbles—just like almost anything else—can be found for sale on the Internet. A company in southwest Oregon—the Glass Bay Studio—sells uterine marbles, deemed “Mareables” for $40 to $50. They come in a variety of sizes, but are all clear and solid. Their web site is www.glassmarble.com.

 

*Glass Balls Mimic Embryonic Development—a research report presented by Auburn University College of Veterinary Medicine’s Drs. Nie, Johnson, Braden and Wenzel, at the 2001 American Association of Equine Practitioners meeting in San Diego.