With all the available assisted reproductive technologies (ART) now available, how do veterinarians decide which technique is best suited for which mare? This subject was discussed in-depth during a Table Topic meeting held during the 2021 AAEP Annual Convention. Session mediators were Hunter Ortis, DVM, from Equine Medical Services, Inc., located in Columbia, Missouri, and Ryan Ferris, DVM, MS, DACT, owner of Summit Equine in Gervais, Oregon.
Faced with a room packed with equine practitioners gazing intensely at him, hoping he’ll solve their breeding conundrums and infertility woes, Ortis explained, “In my practice, we don’t generally decide what procedure we are doing. Usually, the owner has already made that decision!”
Ortis went on to ask, “When you are part of the decision, you need to ask, what are you looking for? One baby, or to maximize a potential number of babies in a certain window of time? Is she a problem mare or a young, healthy show mare?”
In general, there really is no easy way to choose one technique over the other. There are mare, stallion and semen variables that make creating “rules” nearly impossible.
Ortis, whose practice specializes in intracytoplasmic sperm injection (ISCI), typically recommends this assisted reproductive technology (ART) over embryo transfer (ET).
“Especially when you have one straw, one shot and know nothing known about stallion,” Ortis said.
In contrast, Ferris admitted to often using his gut feeling in light of the fact there is never an easy answer.
“If a mare doesn’t give us a reason not to do ET—such as an unappealing uterus full of debris—then I typically recommend starting with ET,” said Ferris. “If an owner is on the fence and was previously successful with ET, I would stick with ET due to more consistent results and lower costs.”
Ortis added, “If you find that you’re spending a lot of time dealing with fluid after breeding in the ET program, then I recommend moving to ICSI.”
Financially, an “easy” ET mare that doesn’t require a lot of post-mating treatments will be less expensive than performing ICSI. If you’re faced with a problem mare that will likely require many treatments, it is probably cheaper to move to ICSI, especially when you add in the costs to ship semen for every ET, advised the experts.
Ortis and Ferris pointed out that while historically ICSI was considered “a tool for problem mares,” this ART has become popular in young, healthy mares without fertility issues. It has, in fact, taking off to such an extent that many reproduction centers are offering what could be described as “drive through aspiration services.”
“People are traveling out of state to line up at our hospital for aspiration,” said Ortis. “Almost immediately after the oocyte aspiration procedure, the mares are loaded back onto the trailer and taken home. ICSI is a major convenience factor for the client.
Ferris explained that the mares in his practice are typically dropped off on a Monday afternoon (for example), aspirated on Tuesday, and discharged on Wednesday morning. Ortis, however, said he allows mares to be shipped back home as soon as they recover sufficiently from sedation and administering a prophylactic antibiotic.
In sum, when helping a client choose between ET and ICSI, Ferris and Ortis highlighted the following:
- Don’t get locked into anything! Give one ART a try and if it’s not working, then change;
- The choice between ET and ICSI is often client driven; and
- Be sure to relay to your client that nothing is guaranteed.