|Nurturing maximal reproductive
performance is much more than a 'diagnosis and treatment' approach.
As is the case with males, female reproduction is in part dependent upon proper nutritional support, adequate exercise, and minimizing stress. Unlike males, we are rarely concerned about 'promotion' of the animal's attributes (with the exception of offspring or embryo sales), and thus focus on individual aspects of pre-breeding management, conception, pregnancy support, delivery (parturition), and dam/neonatal aftercare.
Pre-breeding management includes the evaluation of the dam's prior reproductive history, particularly if there have been any past difficulties. We then evaluate her current condition, and make amends if any updating of health care or nutritional condition is advisable. Females of most species are most fertile if on the "thin side of normal", but in the process of gaining weight. This is not always an attainable goal; it takes time to thin down obese individuals, and you can't keep a dam that repeatedly fails to conceive on a rising plane of nutrition, either.
Nurturing conception boils down to putting high-quality semen into the proper place at the proper time, and into an environment ready to receive it. We may need to monitor the dam for potential infections, treat a variety of reproductive problems medically, alter nutrition, and on rare occasions even recommend changing sires (occasional antibody problems can develop with repeated exposure to sperm from the same sire). Above all, we must monitor the estrus cycles and behavior of the dam, as her interest in the process lets us know when to get involved. At our facility, we have resident "teasers"; a pony stallion, bulls, and a "cystic" cow; whose job it is to assist us in monitoring the oftentimes subtle changes in behavior exhibited by our patients. Observation of that behavior, even at night, is a critical part of our job, and in ultimate success rates.
Once our patient is pregnant, most are taken home by their owners. Upon departure, we supply a custom schedule of recommended pre-delivery health care procedures, and a predicted "due date". At least one "recheck" assessing the progress of a pregnancy, particularly in the first trimester, is often recommended, as it is during the earliest weeks that pregnancy loss is most likely. The development of an embryo from conception to birth is still a little-understood process, but does involve a continuous and evolving "communication" between embryo and maternal uterus prior to implantation. It is during this early stage that "errors of communication" can end the process, and thus a basic explanation for why pregnancy losses are most likely early on. Minimizing stress to the dam is an important supportive action during this period. For example, mares who are difficult and nervous 'haulers' are best advised to 'stay put' until 50 or more days along, and providing adequate shade and cool water during hot summer weather to cows and ewes can dramatically improve pregnancy rates.
Parturition, the most important moment in the eyes of most owners, is certainly a momentous event for the participants as well. While nature has developed a surprisingly trouble-free system for this, problems can and do occur. Valuable animals may be monitored at this critical time, should assistance be necessary, and we offer this service with veterinary attendance 24 hours per day. Because too much attention and human presence near the dam close to delivery can actually enhance the liklihood of complications by making her nervous, we monitor our patients 'remotely', by the use of video cameras and/or tiny, radio-transmitter alarm systems, secured to the vulva long before delivery. With a typical foal delivery, for example, which is most likely to occur between midnight and 3 a.m., early dilation will set off the radio transmitter, sounding an alarm which awakens the veterinarian in attendance. The progress of the delivery can then be monitored through the video cameras, eliminating the need for disturbance of the mare unless absolutely necessary. Once the foal is delivered, initial treatment of the umbilical stump and close-up assessment of both mare and foal can be quietly accomplished while the mare is resting.
Postpartum management involves initial assessment of the physical condition of the newborn, treatment of the umbilical stump with a non-irritating disinfectant to prevent 'navel-ill', examination of the dam to be sure that colostrum production and nursing are normal, that no damage to the reproductive tract occurred, and that the placenta is passed intact. Most owners requesting monitored parturition also want us to spend time during those first hours and days "imprinting" the offspring, a gentle handling process which rapidly accustoms the newborn to human presence and handling without disrupting the normal interaction with the dam. Of course this is not easy to do if the dam does not feel comfortable with the person doing the "imprinting", hence the importance of allowing the expectant mother time to "settle in" at our facility prior to delivery. So little time spent with the offspring right after birth, makes it so much easier to work with the animal throughout the rest of its life. If you don't believe this, come visit, and ask to take a look at Gambler ET, our first frozen embryo transfer. Now a 2000 pound bull, he comes when you call him, is halter broke, picks up his feet like a horse, can be ridden without any halter or bit (we'll let you go for a ride!), and even provides semen samples with just a plastic bag...........
Further services may involve rebreeding the dam, performing the initial series of vaccinations of the young offspring, and further handling or training of the youngster. Most of our handling and training procedures are included in our Board fees, and are not at extra charge.
One of our more recently introduced procedures is the surgical reduction of equine twins where pregnancy has advanced beyond the 28 to 30 day stage, when the embryos become too large to successfully be reduced through the nonsurgical "pinch" method. Those familiar with horse breeding know that about 25 percent of all conceptions are believed to initially be twins, and that typically this number is naturally reduced to a single fetus by day 35. Twin pregnancies in mares that are carried beyond this stage are almost always aborted later in gestation, with only about one in ten thousand births actually resulting in live twins. If we can, we thus want to "abort" one of the twins in order to save the other.
This can be accomplished with about a 75% success rate prior to 28 days of pregnancy by a simple "pinch" technique, involving isolation of the embryo judged least likely to survive by ultrasound and manual palpation, then crushing the conceptus by manual pressure per rectum. This is done without anesthesia, and normally without sedation, as there is no discomfort to the mare involved. Once the pregnancy proceeds beyond 28 days, however, the success rates (determined by survival of the untouched conceptus) drops dramatically with each additional day (to zero after 33 days of gestation), as the local inflammatory response subsequent to the loss of the pinched twin becomes so great that both embryos succumb. Sometimes, for various reasons, twins may not be discovered until well after this window of opportunity.
A more exotic technique employed with some success the past few years in pregnancies further advanced, has been the ultrasound guidance of a long needle through the cranial vaginal wall, through the uterine wall, and into the object fetus' heart, where a small amount of sterile potassium chloride is injected. This potassium overload stops the heart of the fetus, and that fetus "mummifies", allowing the twin to proceed with development. This, however, is a difficult procedure to do, as the needle is introduced more or less parallel to the structures involved, not at right angles to it. Also, the object fetus is typically at least 15 inches away from the surgeon, and there is less room to maneuver within the pelvic cavity.
Dr. Mennick attempted this technique once, and finding it too difficult to comfortably perform on his patients, devised an alternative method that has worked well, takes significantly less time, and seems no more stressful to the patient. This also involves a surgical approach with a long needle, but through the left flank, not the reproductive tract. A traditional, surgical approach is used in the standing horse, using only sedation and local anesthetic. Wearing a sterile sleeve, of course, the surgeon can quickly reach into the abdomen, locate the selected fetus, and regardless of which uterine horn it is in, retract it close to the incision. By this method, the fetus is firmly grasped and controlled, and the approach with the needle is at right angles to it. Injection may be performed anywhere in the thoracic or abdominal cavity with success; the average amount of time involved in the mare's abdomen is just a minute or so, as opposed to possibly several exasperating hours by the other technique.
To date, five of these procedures have been performed, ranging from 64 to 92 days of gestation. In one case, the pregnancy was advanced enough that the uterus was too large to allow adequate stabilization of the selected fetus, and proper injection was not possible. The mare went on to deliver two live twins. In one instance, both fetuses were subsequently lost, and the remaining three were completely successful, i.e. the selected fetus was mummified, the remaining fetus went on to experience normal, healthy delivery, and the mare experienced no complications whatsoever. At this point, we advise that the patient be evaluated for this procedure as soon as possible after 60 days, and that much after 90 days it may be more difficult and less successful.