When a mare is in trouble during foaling, a referral hospital might be the best option for survival of the mare and foal. Dystocia (difficult birth) is a true emergency where minutes count, emphasized Rolf Embertson, DVM, Dipl. ACVS, of Rood and Riddle Equine Hospital in Lexington, Ky., in his presentation "Dystocia Management" during the in-depth session on "The Foal: Birth to One Month."

Incidence of dystocia is around 4%, although this varies by breed, Embertson said. While many dystocias are resolved on the farm, some cases need to be referred to a hospital. This decision should be made based on the position of the foal, duration of the dystocia, distance to and preparedness of the referral hospital, and the experience of the farm's foaling personnel and veterinarian.

Embertson said that at Rood and Riddle, all on-call staff should be within 15-20 minutes of the clinic while on call. When they are notified of an incoming dystocia, the dystocia and neonate teams can organize and be prepared for the mare within 20 minutes. The mare is brought into an induction stall, where she is quickly examined. Usually, assisted vaginal delivery (AVD) has been attempted at the farm. This is when foaling personnel have tried to assist the mare by manipulating the foal through her vagina.

Controlled vaginal delivery (CVD) is the next step at the hospital. The mare is sedated with xylazine and anesthetized with diazepam and ketamine. She is then hooked to a hoist by her back feet ("mare in the air" technique) and her pelvis is lifted three feet from the floor. The veterinarian can then assess the position of the foal and reposition if needed, using the added assistance of gravity to push the foal back into the uterus to give him room to work.

During all of this, the mare is being prepped for a Caesarean section. Since minutes count, if a C-section is necessary, the mare is ready to be whisked away to surgery if fetal manipulation isn't successful.

If the head and forelimbs can be assisted out, then the mare is lowered and traction is applied to the foal for the rest of the delivery. The umbilical cord is then clamped and cut, and the foal is transferred to the neonate team for resuscitation and stabilization.

If a foal cannot be delivered with CVD within 15 minutes, the veterinarian will decide on either a C-section or a fetotomy if the foal is dead, Embertson said. In a fetotomy, the dead foal is cut into more than one piece for easier extraction. At this point, the goal is to minimize trauma to the mare's reproductive tract. Embertson said his preference is to perform a C-section, whether the foal is dead or alive.

During a C-section, the mare's abdomen is cut open and the veterinarian determines which uterine horn contains the foal's hind limbs. This uterine horn is pulled out, cut open, and the foal is grasped by the legs, pulled out, and handed over to the neonate team. Then the surgeon will separate the chorioallantois (fetal membrane) from the endometrium, control uterine bleeding, and suture the mare's uterus closed. The abdomen is washed and closed. After recovery from surgery, the mare is given oxytocin to assist in uterine contraction and expulsion of the placenta, which usually happens six to 12 hours after surgery, Embertson explained.

Embertson also discussed results of a retrospective study done at Rood and Riddle evaluating dystocia statistics of cases from 1986-1999. Out of 247 cases (with 83% being Thoroughbreds), 71% were resolved with CVD, 25% with C-section, and 4% underwent fetotomy. Controlled vaginal delivery was tried first in all cases. Out of 247 cases, 226 (91%) resulted in survival and discharge of the mare, he said, with 94% of these mares undergoing CVD, 89% C-section, and 56% fetotomy. A live foal was born in 104 (42%) of the cases, with 73 (30%) surviving to discharge. Both C-section and CVD were similar in foal discharge rates.

Embertson also said that the elapsed time from chorioallantoic rupture (the mare's water breaking) to delivery for foals alive at discharge at 71.7 (+/-34.3) minutes was significantly lower than foals that did not survive at 85.3 (+/-37.4) minutes.

"This information strongly supports what equine practitioners have known for years--duration of dystocia plays a large role in foal survival," he said.

In the same study, he was surprised to find that of discharged mares bred back that same year, 59% had a foal the following year. Examining fertility in mares after a C-section, another study noted that the live foaling rate was 75% before the C-section and one year after the C-section 41% of those bred back had a live foal. Embertson pointed out that the mare will have a greater chance for a live foal as more time passes after a C-section.

He closed by saying that there is always room for improvement in dystocia management.

About the Author

Sarah Evers Conrad

Sarah Evers Conrad has a bachelor’s of arts in journalism and equine science from Western Kentucky University. As a lifelong horse lover and equestrian, Conrad started her career at The Horse: Your Guide to Equine Health Care magazine. She has also worked for the United States Equestrian Federation as the managing editor of Equestrian magazine and director of e-communications and served as content manager/travel writer for a Caribbean travel agency. When she isn’t freelancing, Conrad spends her free time enjoying her family, reading, practicing photography, traveling, crocheting, and being around animals in her Lexington, Kentucky, home.

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