Reproduction
Mare Breeding Soundness Exam
A thorough examination of your mares reproductive tract to determine suitability for future breeding. This provides the opportunity to examine cervical, uterine and ovarian follicular activity through the use of transrectal ultrasonography. The ability to quantify ovarian follicular activity, uterine edema and cervical tone is important in determining ease of future breeding and likelihood of achieving pregnancy. A diagnosis of intrauterine fluid, or endometrial cysts is very important. Problems such as this would need to be diagnosed and treated prior to breeding for a successful outcome. It is at this point that a preebreeding screen should be done. This is a procedure where a uterine culture and cytology and cervical exam are completed. The culture and cytology provides information about bacterial populations and inflammatory cells present within existing fluid in the uterus. If a bacterial infection does exist, an antibiotic sensitivity can be done so that the infection can be appropriately treated. This is mostly seen on mares that have been bred before and that have had previous pregnancies. Treatment usually involves uterine lavage with fluids and/or an antibiotic infusion for a few days. The cervical exam will note the presence of scarring and an appropriate degree of tone or relaxation. A vaginal exam should be done at the same time to note any scarring, tearing, presence of a persistent hymen (maiden mares), urine pooling, or poor external vulvar conformation allowing "wind sucking" or fecal contamination. The need for a caslicks procedure can be discussed at this time if your mare is at risk for this. It is often helpful to have all of this completed early in the year so that your mare can be ready in time for breeding season.
Artificial Insemination
This is the process where an appropriate volume of shipped, cooled, or fresh semen is aseptically deposited into the uterus at a time that maximizes the chance of conception. This is done in conjunction with sequential ultrasound examinations of the ovaries, uterus and cervix. Most of the time the mare will be given an injection of Lutalyse to synchronize her heat cycle and bring her into heat at a consistent and predictable time. This insures that an ovulatory follicle will develope and grow at a predictable rate. As the follicle enlarges, the developement of uterine edema and cervical relaxation continue to progress. Timing of semen collection and delivery will be important. When the time is right, semen is placed inside of the cervix into the uterus. This is usually a much smaller and cleaner amount than would happen under natural breeding conditions. The semen is also analyzed for concentration, progressive motility and morphology both at the time of collection and insemination. It is extended with nutrients and antibiotics that allow it to survive shipment and insemination into the mare. The goal is to achieve ovulation of the follicle within the next 24 hours. The mare will often be given an injection of hCG (human chorionic gonadotropin) to help this. She will need to be checked for ovulation and the developement of uterine fluid in response to the insemination.
Prenatal Mare Care
Early pregnancy identification (14-18 days) makes it possible to identify at risk pregancies such as twinning. Twins need to be reduced early on to reduce risk to the mare. Often at this time, one embryo can be "pinched" allowing the other to continue to grow. It is also possible to identify early embryonic death at this time. Some mares are susceptible to this, and there can be many causes for it, some not easy to identify. It is important to know so that if the owner desires rebreeding, that enough time is left in the breeding season to do this. At risk mares can have progesterone levels monitored and supplemented if necessary. Once a normal, healthy pregnancy has been established, it is important to follow these mares throughout their pregnancy to monitor fetal health and size. The health and weight of the mare will be important to follow too. Many will need nutritional alterations in the last trimester of pregnancy and through out lactation to help them maintain weight and milk production. This may differ based on breed. They will also need to be dewormed and vaccinated appropriately by a veterinarian during pregnancy. Correct vaccination and deworming will protect the health of your mare and foal during pregnancy and provide the necessary immunity in the colostrum for the foal after birth. Ask your veterinarian to help develope a suitable protocol for each horse.
Post Foaling Examination
Examination of the mare and foal at 24-36 hours of age is necessary to insure their health and survival. Examination and observation of all body systems should be done at this time for both the mare and the foal. It is important that the foal be able to ambulate, nurse productively, pass meconium (first stool) and be observed urinating normally during the first several of hours of age. Often a fleet enema is administered to aid with the passing of the meconium. The mare should also pass the entire placenta within the first couple of hours. Once expelled, it should be saved for the veteriarian to examine. A retained placenta can be a life threatening condition for a mare. If all of this has not happened, it is important to be in communication with your veterinarian for instructions. The umbilicus should also be examined and soaked in dilute chlorhexidine solution 2-3 times daily for the first couple of days. This will reduce the chance of an ascending umbilical infection starting. Blood should also be drawn from the foal at the time of examination to make sure that enough immunoglobulins were consumed from the colostrum (first milk). A foal recieves all immune protection from the mare through the consuming of colostrum in the first 24 hours of life. This colostrum is often thicker and richer than a mares normal milk. These immunoglobulins are essential to the foals survival and protects them against disease and aids in developement of their immune system. After 24 hours, a foal is no longer able to absorb this through the the GI tract. If the foal does not recieve enough immunoglobulins or the mare does not produce enough in her colostrum, then failure of passive transfer has occured. It is important to know this, so that the foal can recieve alternate protection. This is often in the form of a plasma transfer. At the time of examination it is also important to examine the mares vaginal area for tearing and to make sure that she has appropriate udder developement and milk production. We also recommend at this time to give the foal an injection of selenium and start them on probiotics to help colonize the GI tract with bacteria necessary for healthy digestion.
Castration
A surgical procedure performed on juvenile or adult males to remove the testicles on an individual not destined for future breeding and/or to improve their behavior. Some types of stallion behavior are learned and will remain in a castrated individual if the procedure is not performed until later in life. This procedure is performed under field conditions with injectable anesthesia.
