Texas Equine Veterinary Association

www.texasequineva.com • 8 clamp is a useful addition to keep the tubing on the threaded hose barb adaptor when the water is turned on and pressure increases in the system. Alternatively, if a water hose adaptor is unavailable, a clean or sterile drench pump can be fit to a small bore tube and utilized to pump water into an umbilical vessel. The major drawback of using a pump is that an extra person is needed to pump the water, several buckets of water are needed, and the pressure build up in the system can make pumping difficult. In order to perform this procedure, the umbilical vessels of the placenta need to be intact. After cleaning the perineal region of the mare, a small incision is made using a scalpel into one of the umbilical vessels. The small bore tube, which is connected to the water hose attachment, is then inserted into the incised umbilical vessel and placed as far into the umbilical vessel as possible. The tube is held in placed by the operators hand and the water is slowly turned on and adjusted based on the mare's comfort level. When the mare acts uncomfortable, the flow is stopped for a few minutes and placental attachment is evaluated. If the fetal membranes are still attached, flow is slowly resumed and after 3 to 5 minutes gentle traction is applied to the fetal membranes and continued until the fetal membranes are released (Meijer et al., 2015). There is a video online demonstrating this technique at http://youtu.be/ mfjR-MTg6ng. In the author's experience, this technique works in approximately half the retained fetal membrane cases attempted and has not been successful in mares that have either aborted or foaled prematurely. In conversations with other veterinarians who have utilized this technique, mixed success has been reported. Approaching the Problem When confronted with retained fetal membranes, remember to start by thoroughly cleaning the perineal area and exposed placenta before examining the mare vaginally. Prior to a manual vaginal examination, a gentle tug can be given to the external placenta if visualized. On occasion, this is enough to dislodge the fetal membranes. Next palpate the mare vaginally, if the placenta is visualized externally, run your hand gently along the area between the uterus and chorioallanois to determine the degree and location of attachment. If the placenta separates easily from the endometrium, continue until it no longer does so, stop and move to another area. In cases when a fragment of the placenta is retained, usually at the tip of the non-gravid horn, it can be easier to reach the tip of the right horn using the left arm to palpate and then switch arms using right arm to palpate the left uterine horn. At this point, if the placenta is still retained, and the umbilical vessels are intact, the author prefers to use the "Dutch" technique. If the fetal membranes are not expelled using the "Dutch" technique in 10 to 15 minutes, either a lavage or Burn's technique is then used. The uterus is then lavaged until either the fetal membranes are expelled or the fluid recovered is relatively clear. If the fetal membranes are still retained at this point, the mare is treated systemically with broad spectrum antibiotics, a nonsteroidal anti-inflammatory drug, and oxytocin. Some practitioners may also elect to place ice boots on the front hooves as well. If it is suspected, based on placental evaluation, that a fragment of the placenta is retained, first locate the placental fragment. If enough of the placental fragment is loose, this tissue can be gently twirled around your finger. This can create enough traction for the fragment to dislodge on some occasions. In either case, whether the fragment is removed or not, the uterus is then lavaged until the fluid recovered is relatively clear. If the fragment was not removed, an exam glove can be filled with water and umbilical tape used to secure the glove to the placenta. This is done by making a loop and lassoing the fetal membrane with the umbilical tape. Next, the glove is tied to the free end of the umbilical tape so it hangs just above the mare's hocks. This provides traction on the retained placental fragment and can expedite its passage. A word of warning, don't put too much water in the glove, as too much weight can result in tearing the placenta rather than providing traction. Mares are then medically managed as previously discussed above. Treating retained fetal membranes can require patience as it may take several days to pass. It is important not to rush to remove the placenta and cause trauma to the uterus. It is also important that mares are lavaged daily and placed on broad spectrum antibiotics, a nonsteroidal anti-inflammatory drug, and oxytocin until the fetal membranes have passed. These treatments seek to reduce uterine contamination, minimize the likelihood of endotoxemia and prevent laminitis. References Brinsko SP. 2001. How to perform uterine lavage: indications and practical techniques. Proc Am Assoc Eq Prac. 47: 407 – 411. Burden CA, M Meijer, M Pozor, and M Macpherson. 2019. Fetal membrane removal in the mare. Vet Clinics: Eq Pract. 35: pp 289 – 298. Burns SJ, NG Judge, JE Martin and LG Adams. 1977. Management of retained placenta in mares. Proc Am Assoc Eq Prac. 23: 381– 390. Campbell MLH and GCW England. 2002. A comparison of the ecbolic efficacy of intravenous and intrauterine oxytocin treatments. Therio. 58: 473-477. Canisso IF, JS Rodriguez, MG Sanz and MA Coutinho da Silva. 2013. A clinical approach to the diagnosis and treatment of retained fetal membranes with an emphasis placed on the critically ill mare. J Equine Vet Sci. 33: 570–579. Cuervo-Arango J and JR Newcombe. The effect of manual removal of placenta immediately after foaling on subsequent fertility parameters in the mare. J Equine Vet Sci. 29: 771 – 774. Lopate C, M LeBlanc, R Pascoe and D Knottenbelt. Parturition. Saunders, London (United Kingdom); 2003. Meijer M, M Macpherson and R Dijkman. 2015. How to use umbilical vessel water infusion to treat retained fetal membranes in mares. Proc Am Assoc Eq Prac. 61: 478 – 484. Sevinga M, JW Hesselink and HW Barkema. 2002. Reproductive performance of Friesian mares after retained placenta and manual removal of the placenta. Therio. 57: 923 – 930. Threlfall, W.R. Retained fetal membranes. 2nd edition. Blackwell Publishing, West Sussex (United Kingdom); 2011. Vandeplassche M., J Spincemaille, R and Bouters. 1971. Aetiology, pathogenesis and treatment of retained placenta in the mare. Equine Vet J. 3: 144–147. Warnakulasooriya DN, CD Marth, JA McLeodm, DW Hanlon and N Krekeler. 2018. Treatment of retained fetal membranes in the mare – a practitioner survey. Front Vet Sci. 19: doi: 10.3389/ fvets.2018.00128.

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