Right dorsal colitis in horses: A multicenter retrospective study of 35 cases.
Authors: Flood Jordan, Byrne David, Bauquier Jennifer, Agne Gustavo Ferlini, Wise Jessica C, Medina-Torres Carlos E, Wood Kelly, Sullivan Olivia, Stewart Allison J
Journal: Journal of veterinary internal medicine
Summary
# Right Dorsal Colitis in Horses: What a Multicentric Australian Study Reveals About NSAID-Induced Injury Right dorsal colitis represents a serious protein-losing enteropathy in horses, yet clinical recognition and understanding of risk factors remain limited; this retrospective analysis of 35 cases from seven Australian hospitals sought to characterise the condition's presentation, pathophysiology, and prognostic indicators. The research team reviewed diagnostic criteria including hypoproteinaemia, negative infectious disease testing, clinical signs of colic or diarrhoea with imaging evidence of right dorsal colon wall thickening, then analysed associations between presenting parameters and survival outcomes using logistic regression. NSAID overdosing accounted for 84% of cases where medication history was documented, with affected horses typically presenting with diarrhoea (69%), colic (61%) and tachycardia (53%), alongside consistent laboratory findings of hypoalbuminaemia (83%), hypocalcaemia (79%) and hyperlactatemia (77%); ultrasound visualised colon wall thickening in 77% of cases. Overall mortality was 43%, but survival was significantly compromised by elevated heart rate, elevated packed cell volume, and abnormal mucous membrane appearance on admission—all indicators of systemic compromise or advanced disease. For practitioners, this study underscores the critical importance of NSAID dosing accuracy and duration monitoring, particularly the need for regular serum albumin assessment during prolonged anti-inflammatory therapy. The fair prognosis and high case fatality rate demand early recognition of clinical signs and aggressive supportive management, whilst the strong association between admission vital signs and outcome supports rapid assessment of cardiovascular stability and perfusion status as key decision-making tools.
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Practical Takeaways
- •NSAIDs are frequently overdosed in horses with RDC; verify dosing protocols and monitor serum albumin concentrations during prolonged NSAID therapy to detect early protein loss
- •Horses presenting with elevated heart rate, high packed cell volume, or abnormal mucous membranes have significantly worse prognosis; consider early aggressive intervention and close monitoring in these cases
- •RDC carries substantial mortality risk (43%); maintain high clinical suspicion in horses with diarrhea, colic, and hypoproteinemia that test negative for infectious causes
Key Findings
- •NSAID overdose occurred in 84% of cases where dosing information was available
- •Case fatality rate was 43%, with increased heart rate, packed cell volume, and abnormal mucous membranes significantly associated with decreased survival odds
- •Hypoalbuminemia (83%), hypocalcaemia (79%), and right dorsal colon wall thickening on ultrasound (77%) were common clinicopathological findings
- •Diarrhea (69%), colic (61%), and tachycardia (53%) were the most common clinical presentations