Ask the Vet: Reproduction

Question: How soon after delivery can a mare be bred back to another stallion? What are the positives and negatives for not allowing suitable time for recovery from foaling?

Answer: Most mares foaling during the breeding season (long days), will come back into heat around day 7 after foaling. This is called their foal heat. The foal heat can be a fertile cycle to breed her, as long as there were no major complications during foaling. Pros can be getting your mare in foal earlier in the year. Some issues that may complicate a foal heat breeding would be trauma to the reproductive tract during foaling, retained placenta and complications from that, exceed fluid or debris that hasn’t been pushed out. Sometimes there is added difficulty in retrieving an embryo from a bigger uterus on a foal heat breeding before it returns to its normal size once again. In my practice, I encourage a full examination of the mare’s reproductive tract to look for these potential issues and that’s a great time to get the foal examined again too. We breed many mares each year on foal heat and have great successes with it. Dr. Semira Mancill, Weatherford, TX

Question: Is there an age limit for a mare to be fertile? I have a mare that I am unfamiliar with her history. I am also uncertain that she has had a cycle in the last 4 months. She is11-years-old.

Answer: There is no set age limit in mares as some mares can be fertile into their 20’s. Your mare is not old, by fertility standards. This time of year is tricky for horses. They go into a “quiet” time for fertility, called anestrus, in the winter, when they don’t cycle at all. Then, in the spring as the days begin to get longer, they will transition into cyclicity once again. So, your mare is likely right on track as horses are “long day breeders.” A simple palpation/ultrasound by your veterinarian can tell you where your mare is in her cyclicity. Dr. Semira Mancill, Weatherford, TX

Question: My 10-year-old mare has MILK and as far as I know is NOT pregnant…she doesn’t look pregnant either. She has had two foals before I purchased her 6 years ago. Should I be concerned?

Answer: There are several reasons your mare could have discharge from her mammary glands, including pregnancy, mastitis (infection in the gland), or some produce fluid for unknown reasons that are not harmful to the mare. If the mare is at your place with NO intact males, including young colts around in the last year, then pregnancy is probably low on the list. Mastitis can look as simple as just an increase in size of the mammary gland with some fluid discharge all the way to highly increased in size, hot, painful and include foul discharge. Although some mares can normally have fluid discharge without disease or pregnancy, a simple check-up with your veterinarian can rule out these reasons and give you an answer to let you rest easy about your mare. Dr. Semira Mancill, Weatherford, TX

Question: My new broodmare, I hope to breed, has very large mammary glands from past breedings. Will this be a problem for a new born foal?

Answer: Sounds like you have a nice broodmare on your hands! Previous pregnancies can alter the maiden mare’s mammary glands over the years, causing them to stay in a somewhat enlarged state. As long as she doesn’t have signs of mastitis or infection of the mammary glands, such as heat, pain, or foul discharge, she should be just fine. Happy breeding season! Dr. Semira Mancill, Weatherford, TX

Courtesy of AAEP