Texas A&M removes 13-pound enterolith from mare with chronic colic: full analysis

Texas A&M veterinarians have highlighted a dramatic but clinically familiar equine colic case: a 19-year-old mare, Winterfair, was found to have a 13-pound enterolith that had apparently been driving years of chronic, recurrent abdominal pain. In the university’s account, the stone was surgically removed, and the mare recovered well enough to resume normal eating and behavior, turning a patient story into a practical reminder about one of the more elusive causes of repeat colic. (ceh.vetmed.ucdavis.edu)

The broader clinical backdrop is well established. Enteroliths are mineral concretions, typically composed largely of magnesium ammonium phosphate, that form around a central nidus such as wire, stone, or other ingested material. They’re most often located in the large colon, and many affected horses don’t present first with catastrophic abdominal pain. Instead, they can show intermittent, low-grade, or recurrent colic over time, especially when a large stone temporarily obstructs and then shifts. Merck says many horses with enterolithiasis have a history of recurring colic, while UC Davis notes that a single large enterolith in the large colon may produce chronic, intermittent signs. (merckvetmanual.com)

That pattern helps explain why cases like Winterfair’s can stretch on before a diagnosis is confirmed. Texas A&M’s previously published enterolith case involving another mare, Koche, described the same stop-and-start clinical course, with surgeons noting that stones can lodge, back things up, then move and cause intermittent pain again. In that case, the enterolith was identified and removed surgically after referral to the Large Animal Teaching Hospital, and the clinicians stressed that “minutes count” once a horse with colic is not improving. That earlier report doesn’t describe Winterfair, but it does provide useful institutional context for how the hospital approaches these cases and how Texas clinicians are framing risk and referral. (vetmed.tamu.edu)

On risk factors, the literature is consistent even if individual cases vary. Merck links enterolithiasis with higher mineral concentrations and higher pH in large-colon contents, and identifies alfalfa hay as a common associated factor. Texas A&M’s earlier case report similarly tied one horse’s enterolith risk to an alfalfa-heavy diet and high-calcium water, while noting that the condition is less familiar to many Texas horse caretakers than it is in endemic regions such as California. UC Davis goes a step further on prevention and recurrence, advising that horses recovering from enterolith surgery should not have alfalfa in the diet because recurrence is likely if recommended dietary changes aren’t followed. (merckvetmanual.com)

Expert commentary in the public record is mostly practical rather than speculative. UC Davis describes radiographs as the best screening test, although not every enterolith is visible, depending on horse size, bowel contents, stone location, and equipment. Merck likewise notes that radiography can identify enteroliths in areas where the problem is common, but rectal findings are often nonspecific. The AAEP’s educational materials and proceedings also reinforce the classic presentation: horses with enterolithiasis often have intermittent colic, and some may have a longer presurgical course because the case is initially managed as a partial, nonstrangulating obstruction before the lack of response becomes clear. (ceh.vetmed.ucdavis.edu)

Why it matters: For veterinary professionals, Winterfair’s case is less about the headline weight of the stone and more about the diagnostic lesson. Recurrent colic that repeatedly improves, then returns, can lull teams into a cycle of medical management, especially when signs are mild or nonspecific. But enteroliths are one of the clearest examples of a structural problem that may only be definitively solved with surgery. In referral discussions with pet parents, cases like this can help explain why repeated episodes, diet history, regional risk, and imaging findings deserve to be considered together rather than treated as isolated events. (ceh.vetmed.ucdavis.edu)

The case also underscores the value of referral networks between field veterinarians and equine hospitals. Texas A&M’s prior messaging on enterolith cases emphasizes that early escalation can improve outcomes, and its equine surgery research program is explicitly focused on improving outcomes for colic surgery patients. For practices managing horses in regions where enterolithiasis is considered less common, that may be the most useful takeaway: rarity in a local market doesn’t eliminate the diagnosis, particularly when a horse’s history keeps pointing back to chronic, unexplained colic. (vetmed.tamu.edu)

What to watch: The next useful development would be a fuller clinical case description from Texas A&M or the authors, including imaging findings, surgical details, and any postoperative nutrition changes, because those specifics would help translate a compelling patient story into a more actionable teaching case for equine practitioners. (vetmed.tamu.edu)