Recurrent Colic: What the Research Says
Evidence from 19 peer-reviewed studies
What Professionals Should Know
- •Some horses appear predisposed to recurrent colic due to inherent microbiome composition rather than diet alone—individual microbial profiling may help identify at-risk horses for targeted preventive management
- •Horses prone to colic show dysbiosis characterized by reduced bacterial diversity and Streptococcus dominance; monitoring fecal lactate levels or microbiome composition could support early intervention strategies
- •Fiber-degrading bacteria appear protective against colic; management strategies that promote these beneficial taxa (through forage quality, prebiotics, or targeted feeding) may reduce recurrence risk in susceptible individuals
- •Pregnant mares presenting with colic carry significant mortality and morbidity risk; elevated lactate and packed cell volume at admission are strong warning signs that warrant aggressive intervention and close monitoring
- •Nearly half of discharged pregnant colic patients develop recurrent colic—close post-discharge monitoring is essential, particularly for Thoroughbreds; consider preventive management protocols
- •Development of diarrhea or SIRS during hospitalization carries very high risk for pregnancy loss—early recognition and intervention (including altrenogest therapy if indicated) may improve outcomes
- •Source of horse purchase (Europe vs Ireland) appears to be a significant risk factor for colic susceptibility—consider this in acquisition and pre-purchase assessment protocols
- •Despite strict military management regimens, colic rates remain comparable to general populations, suggesting that other intrinsic or pre-existing factors (possibly related to previous management or genetics) may outweigh standardized management practices
- •One-third of horses that colic once will colic again—implement focused monitoring and preventive management for horses with colic history, as most episodes are managed medically rather than surgically
- •Prophylactic nephrosplenic space closure effectively prevents recurrent LDDLC and reduces overall colic incidence in affected horses
- •Horses treated medically for LDDLC without surgical closure have significantly higher colic recurrence rates and warrant consideration for preventive surgery
- •This procedure should be discussed with owners of horses presenting with LDDLC as a strategy to improve long-term outcomes and reduce future colic episodes
- •Horses exhibiting stereotypic behaviours (crib-biting, windsucking, weaving) should be considered higher-risk for recurrent colic and warrant enhanced preventive management strategies
- •Maximizing pasture access appears to be a practical and evidence-supported approach to reducing recurrent colic risk in susceptible horses
- •Individual horses identified with behavioural risk factors should have their feeding and management practices carefully reviewed and optimized as part of colic prevention
- •Horses that crib-bite or windsuck should be monitored closely for signs of colic, as they have elevated risk
- •Owners and practitioners should implement preventive management strategies for CBWS horses to reduce colic incidence
- •Early intervention in horses with stereotypic behaviours may help reduce downstream gastrointestinal complications
- •Counsel owners that horses with right dorsal colon displacement have a significantly higher risk of recurrent colic post-operatively compared to other displacement types—set realistic expectations for long-term prognosis
- •Right dorsal displacement should be flagged as higher risk in post-operative management planning; closer monitoring and owner education may reduce complications
- •Consider this higher recurrence rate when discussing surgical versus conservative management options and long-term cost-benefit with owners
- •Most horses with peritonitis can be successfully treated and discharged (86%), making aggressive medical management a reasonable approach in referral cases
- •Long-term prognosis is generally good with 84% surviving beyond 12 months, but monitor discharged horses closely as one-third develop post-peritonitis complications including recurrent colic
- •Identify the underlying cause of peritonitis when possible, as secondary causes (urinary/mass-related) carry poorer prognosis than idiopathic peritonitis
- •Consider viral infection (particularly EHV-1 and EHV-5) as a potential underlying cause in horses with recurrent colic and weight loss unresponsive to standard management over extended periods
- •Myenteric ganglionitis should be included in the differential diagnosis for chronic intestinal pseudo-obstruction; early recognition may lead to improved treatment approaches
- •Advanced diagnostics including PCR testing of intestinal tissues may be warranted in cases of refractory colic with consistent small colon impaction on multiple examinations
- •Pheochromocytomas can be successfully diagnosed and surgically removed in horses; consider this diagnosis in mares presenting with recurrent colic, profuse sweating, and agitation over extended periods.
- •The trans-costal approach with 18th rib removal provides excellent visualization for adrenal mass removal and vessel ligation, resulting in successful outcomes despite potential intraoperative and postoperative complications.
- •Horses can return to athletic use following surgical adrenal mass removal when complications are managed appropriately, offering a realistic prognosis for owners of affected animals.
- •Myenteric ganglionopathies should be considered in cases of recurrent small colon impaction, particularly when conservative management provides only temporary relief and impaction recurs within weeks to months.
- •Exploratory laparotomy with full-thickness intestinal biopsies of the caecum and colon may be necessary for definitive diagnosis when recurrent impaction is unexplained, as standing laparoscopy may not visualize critical pathology.
- •Prognosis is guarded even with diagnosis; severe myenteric depletion associated with chronic pseudo-obstruction can deteriorate rapidly post-operatively, and owners should be counseled on potential poor long-term outcomes.
- •Consider os pubis exostosis in horses presenting with recurrent colic and concurrent urinary dysfunction; rectal examination and cystoscopy can help confirm diagnosis.
- •Laparoscopic resection under general anesthesia is a viable minimally invasive alternative to traditional open surgery for this condition.
- •This technique may reduce postoperative morbidity compared to conventional approaches while achieving excellent long-term clinical resolution.
- •Chronic pyloric lesions should be considered as a differential diagnosis in young horses presenting with weight loss, slow eating, and recurrent colic, particularly if squamous gastric disease is identified on endoscopy
- •Medical management with anti-ulcer therapy achieves initial improvement in most cases (88%), but recurrence is common and long-term prognosis remains poor, especially in horses under 3 years old
- •Early recognition and discussion of realistic prognosis is important, as only 41% achieve long-term survival regardless of treatment approach
- •Prolonged postoperative ileus in horses can resolve with aggressive multimodal management—don't give up on seemingly hopeless cases early in the course
- •Implement early enteral feeding and mobilization as soon as clinically feasible, mirroring human POI protocols, to promote gut motility and recovery
- •Coordinate fluid therapy, prokinetic medication, and nutrition support while allowing time for surgical healing; some cases require 3-4 weeks of intensive care but can achieve full return to work
- •Consider TMJ-DJD in the differential diagnosis for horses presenting with quidding, audible clicking during chewing, or recurrent colic—not all cases result from trauma
- •Advanced imaging (CT/MRI) can confirm TMJ pathology and disc mineralization; intra-articular corticosteroid injection is a treatment option but provides temporary relief requiring repeated interventions
- •Monitor older horses for age-related TMJ degeneration and be aware it may contribute to secondary issues like colic and feed wastage
- •In Friesian horses presenting with recurrent false colic, coughing, tachycardia, or peripheral oedema, include aortic rupture and aorto-pulmonary fistulation in your differential diagnosis—these may be progressive conditions rather than acute emergencies
- •Clinical signs may develop over weeks rather than presenting as sudden death; sustained tachycardia and bounding pulses with oedema warrant cardiac investigation in this breed
- •Post mortem examination of Friesians requires meticulous dissection of the aortic arch near the ligamentum arteriosum to identify ruptures and fistulas; standard techniques may miss these lesions
- •Laparoscopic nephrosplenic space closure is a viable preventive option for horses with recurrent LDDLC, eliminating future displacement of this specific location.
- •Etilefrin-induced splenic contraction facilitates the standing laparoscopic procedure and improves surgical efficiency and safety.
- •Consider this procedure for horses with a history of recurrent LDDLC, as the 21% recurrence rate with standard treatment justifies a more definitive surgical approach.
- •Abdominal ultrasound should be a core diagnostic tool in your colic workup whether you're in ambulatory practice or hospital settings—learn the technique and key normal/abnormal findings
- •Sonography helps differentiate types of colic and guides treatment decisions, reducing unnecessary surgery and improving outcomes for referred cases
- •Stay current with recent developments in sonographic technique as the field continues to evolve and improve diagnostic accuracy
- •Recurrent colic in horses is frequently associated with chronic mucosal inflammation rather than acute mechanical obstruction, suggesting investigation of underlying inflammatory conditions in repeat colic cases
- •Biopsy findings support nutritional and management interventions targeting intestinal health and reducing inflammatory triggers in horses with recurrent colic episodes
- •Shortened villi observed in >25% of cases may compromise nutrient absorption and intestinal barrier function, warranting dietary support and consideration of mucosal healing protocols
Key Research Findings
Horses with a history of colic showed significantly decreased microbial evenness and increased Streptococcus abundance compared to non-colic horses
Fecal lactate concentration was higher in colic-affected horses, potentially driven by elevated Streptococcus populations
Healthy horses were characterized by higher abundance of fiber-degrading bacteria including Rikenellaceae RC9, Kiritimatiellae, and Clostridium
Microbiome composition differences associated with colic risk were independent of identical feeding and management conditions
Survival rate of pregnant mares treated for colic was 70.2% (73/104 admissions); admission hyperlactatemia and high packed cell volume significantly reduced survival (HR 3.24 and 2.89 respectively)
Recurrent colic occurred in 47.1% of discharged broodmares (33/70), with Thoroughbred breed showing 5× higher risk than other breeds
Negative pregnancy outcome occurred in 21.5% of cases (14/65); diarrhea during hospitalization was the strongest predictor (OR 379.3) along with SIRS development (OR 31.2)
Altrenogest administration during treatment was protective against negative pregnancy outcome (OR 0.029), reducing risk by 97%
Colic incidence in British military working horses was 11.1 episodes per 100 horse-years with 22.7% of horses experiencing at least one episode over five years
Colic-related mortality was 0.5 deaths per 100 horse-years (1.8% of population), comparable to general horse population rates
Horses purchased from mainland Europe were 4.6 times more likely to suffer colic and 6.0 times more likely to experience recurrent colic compared to horses from Ireland
Recurrent colic occurred in 35% of affected horses, yet only 3% of colic episodes required surgical intervention
Nephrosplenic space closure resulted in significant decrease in total incidence of colic compared to non-operated horses
No horse developed LDDLC recurrence after nephrosplenic space closure surgery
Follow-up data available for 65% of cohort with mean follow-up of 35 months
Evidence Base
Correlation of hindgut microbiome and fermentation properties with a history of gas and/or impaction colic in Japanese draft horses
Rintaro Yano, Tomoe Moriyama, H. Arai et al. (2025) — Journal of Equine Science
Outcomes of pregnant broodmares treated for colic at a tertiary care facility.
Douglas Hope F, Stefanovski Darko, Southwood Louise L (2021) — Veterinary surgery : VS
Colic in the British military working horse population: a retrospective analysis.
Tannahill Victoria J, Cardwell Jacqueline M, Witte Tom H (2019) — The Veterinary record
Nephrosplenic space closure significantly decreases recurrent colic in horses: a retrospective analysis
J. A. Arévalo Rodríguez, S. Grulke, A. Salciccia et al. (2019) — Veterinary Record
Management and horse-level risk factors for recurrent colic in the UK general equine practice population.
Scantlebury C E, Archer D C, Proudman C J et al. (2015) — Equine veterinary journal
Prevalence of and risk factors for colic in horses that display crib-biting behaviour.
Escalona Ebony E, Okell Claire N, Archer Debra C (2014) — BMC veterinary research
Are horses that undergo an exploratory laparotomy for correction of a right dorsal displacement of the large colon predisposed to post operative colic, compared to other forms of large colon displacement?
Smith L J, Mair T S (2010) — Equine veterinary journal
Study of the short- and long-term outcomes of 65 horses with peritonitis.
Henderson I S F, Mair T S, Keen J A et al. (2008) — The Veterinary record
Lymphocytic myenteric ganglionitis associated with equine herpesvirus infection: A cause of chronic intestinal pseudo‐obstruction and recurrent colic in an adult horse
Magalhães Mariana Torres, Palmers Katrien, De Cock Hilde et al. (2024) — Equine Veterinary Education
Successful surgical removal of a pheochromocytoma in a mare via trans-costal approach.
O'Brien Thomas J, Pezzanite Lynn M, Acutt Elizabeth V et al. (2023) — Equine veterinary journal
Diagnostic and Clinical Course of Small Colon Recurrent Impaction Associated with Severe Myenteric Ganglionopathy in A Mare.
Ortolani Flaminia, Nannarone Sara, Sforna Monica et al. (2021) — Journal of equine veterinary science
Laparoscopic resection of an exostosis of the os pubis in a horse.
Delcazo Mario, Geburek Florian, Köhler Kernt et al. (2020) — Veterinary surgery : VS
Chronic severe pyloric lesions in horses: 47 cases.
Bezdekova B, Wohlsein P, Venner M (2020) — Equine veterinary journal
Successful treatment of prolonged postoperative ileus following resection of a small intestinal spindle cell sarcoma in a horse
Janny C. de Grauw, T. V. Van Loon (2019) — Veterinary Record Case Reports
Clinically significant, nontraumatic, degenerative joint disease of the temporomandibular joints in a horse
Smyth T., Allen A. L., Carmalt J. L. (2017) — Equine Veterinary Education
Aortic rupture and aorto-pulmonary fistulation in the Friesian horse: characterisation of the clinical and gross post mortem findings in 24 cases.
Ploeg M, Saey V, de Bruijn C M et al. (2013) — Equine veterinary journal
Indications, surgical technique, and long-term experience with laparoscopic closure of the nephrosplenic space in standing horses.
Röcken Michael, Schubert Christine, Mosel Gesine et al. (2005) — Veterinary surgery : VS
Abdominal Sonographic Evaluation: In the Field, at the Hospital, and After Surgery.
Cristobal Navas de Solis, M. Coleman (2023) — The Veterinary clinics of North America. Equine practice
Retrospective Evaluation of the Most Frequently Observed Histological Changes in Duodenal and Rectal Mucosal Biopsies in Horses with Recurrent Colic.
Siwińska Natalia, Żak-Bochenek Agnieszka, Paszkowska Marzena et al. (2022) — Animals : an open access journal from MDPI