Equine Matters Spring 2019

Figure 2: An ultrasound picture of the uterus containing an abnormal amount of fluid (black) Is there anything we can do about these problems? Absolutely; l Post breeding endometritis (inflammation of the uterine lining): All mares will have a degree of reaction to semen entering their uterus, but some will react more than others (see Figure 2). If this is not dealt with, when the embryo enters the uterus it cannot survive. This is why vets may ‘wash out’ a mare with sterile saline after they have inseminated her and give her hormones such as oxytocin to cause her uterus to contract and expel fluid. l Sunken vulva: A minor operation called a Caslick’s procedure can be carried out to stitch together the upper part of the vulva. This mimics the natural seal of the normal vulva and stops air from entering. l Cervix: Mares with a tight cervix can benefit from multiple washings of the uterus and sometimes a catheter can be placed to allow fluid to drain out (see Figure 3). This issue normally resolves once the mare foals. l Sagging of the uterus: This is difficult to resolve but some vets have reported positive results using acupuncture. l Uterine infections: These can usually be treated with antibiotics, which are normally put into the uterus itself. Early pregnancy failure After conception, some mares fail to maintain their pregnancy due to impaired hormonal control. Mares with this problem can be treated with progesterone replacement therapy such as Regumate. It is important to realise that there can be other factors that cause early pregnancy loss, including abnormalities of the embryo itself. Unrelated diseases Recognition and treatment of disease is important for fertility. As more older mares are being put in foal, we are recognising that a proportion of these do have PPID. When treated, the mare’s fertility normally improves. However, we have to be aware that pergolide, the most common treatment for PPID, does stop a mare producing milk for her foal, so treatment is withdrawn in the latter stages of pregnancy to avoid this happening. Stallion factors We have explored problems mares can experience when trying to get pregnant. However, we mustn’t forget the stallion. Things like semen quality and performance when using natural cover must be taken into consideration. Sometimes it can be his fault! There are many reasons why mares fail to conceive, but a large number of them can be rectified. The involvement of your veterinary surgeon is crucial when a mare is having problems and a pre-breeding examination is so useful to anticipate these issues. Abnormal anatomy This is a rare but important reason that conception may fail. Occasionally, a filly can be born with an abnormal anatomy that makes it impossible for her to breed. For example, I came across one such animal that had no cervix; this was detected on a pre-breeding exam. If a mare is suffering with a disease it can interfere with getting her in foal. Examples include; l Pars Pituitary Intermedia Dysfunction (PPID, or Cushing’s disease) l Gastric ulcers l Poor body condition l Obesity and Equine Metabolic Syndrome Figure 3: A uterine catheter being stitched into place to allow fluid to drain out of the uterus 14 Equine Matters Spring 2019