Success Story: A Foal's Unconventional Introduction into the World

Colic is every horse owner’s worst nightmare, but when the colicking patient is also pregnant, colic emergencies pose an even bigger challenge for their owner and the team of veterinarians entrusted with their care. In late February, a pregnant mare was brought to Palm Beach Equine Clinic by her owner for colic. Leading the PBEC team on this case were Drs Justin McNaughten DACT, Peter Heidmann, DACVIM, and Elizabeth Barrett, DACVS-LA. We spoke with Dr. McNaughten about the steps he and the team took to keep both the mare and foal safe.

What was the mare’s status when she was admitted to the clinic?

The presenting complaint was colic. At the time of admission, the mare had an elevated heart rate of 120 beats per minute. We then passed a nasogastric tube, which resulted in approximately 15 liters of spontaneous reflux. Once the stomach was decompressed, we proceeded with the rest of the colic work-up. As the mare was in the later stage of pregnancy, the foal occupied the majority of the abdomen. Findings on rectal palpation and abdominal ultrasound were inconclusive. The working diagnosis was ileus or decreased gut motility, but the root cause was still unknown. As part of the medical treatment, the mare had to be fasted. We started her on IV fluids with prokinetics, electrolytes, and dextrose as a source of nutritional support for the foal. Overnight, the mare remained comfortable but continued to have small amounts of reflux. The next morning, she was showing new signs of gas distension, which were not present at the time of admission. An abdominocentesis or ab-tap revealed elevations from the normal peritoneal fluid values suggesting that surgery was warranted.

What factors did you take into consideration before deciding to treat the mare?

When we are dealing with pregnant mares, we often make decisions based on the stage of pregnancy. The biggest obstacle is trying to treat the mare and doing what is safe for the foal in utero. For example, we may use different medications that are safe during one stage of pregnancy and not another, or delay procedures until after the mare delivers the foal. In this case, the owner didn’t have an ovulation date because the breeding had occurred in a paddock. A couple of diagnostic tests can be used to provide a rough estimate of the foal’s gestational age, measuring fetal orbit and the fetal aortic diameter. The results are interpreted as a rough estimate as the reference values have not been determined for each breed. Unfortunately, in the mare, gestation length does not correlate with fetal readiness or her foal’s ability to survive once it’s born. We also performed a diagnostic test to help determine fetal readiness based on evaluating the mare’s mammary secretions. In this case, we specifically measured the pH level.

Based on the mare’s need for colic surgery and the pH levels of her mammary secretions, the team of specialists discussed the options, weighing a fairly extensive list of potential risk factors for the mare and the foal. The owner was presented with the options of performing colic surgery with the foal still in utero or inducing parturition and performing colic surgery once she foaled. At the owner’s request, we induced foaling, which carries its own set of risks and can be life-threatening to both the mare and foal.

In this case, fortune was on our side. Following a successful assisted vaginal delivery, the newborn filly was hitting each of our targets for neonates. Although the filly was not showing any external signs of prematurity, we took radiographs of the knees and hocks as a precaution. The x-rays showed that the filly was a bit premature based on the incomplete ossification of the cuboidal bones, which make up the knees and hocks.

Following the delivery, the mare was then taken into surgery. During the colic surgery, Dr. Barrett identified and removed a very large fecalith, which we assumed was the root of the problem as it had the potential to obstruct the bowel. A fecalith is a hard concretion of ingested material that may increase in size and end up being a blockage in the gastrointestinal tract.

What did their postoperative care look like?

Post-surgery, the mare did very well. While hospitalized, she remained comfortable, tolerated refeeding, and displayed great maternal behavior. The filly was started on prophylactic antibiotics and given milk initially through a feeding tube until the mare had enough milk to sustain the foal. Approximately 48 hours after foaling, the filly developed signs of neonatal maladjustment syndrome, which manifests as neurologic abnormalities. One moment the foal was healthy, bright, and nursing, and the next, she was dull, listless, and disoriented. The condition subsided following IV administration of neuroprotective agents and through the use of the Madigan foal squeeze technique. The Madigan squeeze technique is a physical compression procedure that involves wrapping a foal’s upper torso with loops of soft rope and applying pressure for 20 minutes, which replicates the compression a foal experiences during birth.

After a few days, both mare and foal were discharged to the care of the farm. At home, the pair were placed on stall rest followed by additional exercise restrictions allowing time for the mare’s abdominal incision to heal and the filly’s cuboidal bones to fully mature. Now, exactly one month later, I’m happy to say that both the mare and her foal are thriving.

Palm Beach Equine Clinic is available 24/7 for any equine emergency and works regularly with referring veterinarians. For more information, call 561-793-1599.