RELATIONSHIP BETWEEN SMALL STRONGYLES (CYATHOSTOMINAE) AND HORSE COLIC OCCURRENCE
Journal: Equine Veterinary Education
Summary
# Editorial Summary: Small Strongyles and Equine Colic Whilst small strongyles have long been implicated in colic aetiology, the evidence linking parasite burden to clinical disease remains surprisingly unclear. Researchers compared coprological findings from 43 horses presenting with colic (surgical and non-surgical cases combined) against 43 matched controls, performing faecal egg counts and negative binomial regression analysis to assess the relationship between cyathostomine infection intensity and colic occurrence. Counter to traditional teaching, horses with surgical colic actually carried significantly lower small strongyle burdens (mean 68.6 EPG) compared to healthy controls (178.1 EPG), whilst those with non-surgical colic showed no significant difference; older horses also demonstrated lower egg counts regardless of colic status. The findings suggest that heavy small strongyle infections may not directly precipitate colic in the way previously assumed, and intriguingly propose that establishing a higher burden of luminal adult parasites might paradoxically protect against mucosal larval emergence—or alternatively, that rigorous management practices reducing colic risk simultaneously increase infective larval exposure. For practitioners, this implies that small strongyle faecal egg counts alone should not be weighted heavily in colic diagnosis or prevention strategies, and that anthelmintic protocols merit re-evaluation against current epidemiological evidence rather than historical assumptions.
Read the full abstract on PubMed
Practical Takeaways
- •Higher strongyle burdens appear protective against surgical colic rather than causative—challenge current assumptions about small strongyles and colic risk
- •Parasite management practices that reduce surgical colic may paradoxically increase larval exposure; consider integrated risk assessment rather than parasite burden alone
- •Strongyle EPG testing has limited clinical utility for predicting non-surgical colic occurrence in individual horses
Key Findings
- •Small strongyles were found in 34/86 horses (39.5% prevalence) with mean EPG of 145.34
- •Horses with surgical colic had significantly lower EPG (68.6) compared to controls (178.1, p<0.05)
- •No significant difference in strongyle EPG between non-surgical colic cases and controls
- •Negative relationship between age and EPG (p<0.05); sex had no influence on EPG