Prevalence and diagnosis of parasites of the stomach and small intestine in horses in south-west England.
Authors: Morgan E R, Hetzel N, Povah C, Coles G C
Journal: The Veterinary record
Summary
Gastrointestinal tapeworms, particularly *Anoplocephala perfoliata*, represent a significant parasitic burden in UK horses, yet diagnosis during life has proven challenging; Morgan and colleagues examined post-mortem specimens from 118 South West England horses to establish the relationship between worm populations and serological detection. Using maximum likelihood analysis, researchers quantified both parasite numbers and total biomass from stomach and small intestinal samples, then correlated these findings against antibody levels detected via ELISA testing. The data revealed density-dependent constraints on tapeworm growth—as parasite numbers increased, individual worm weight plateaued rather than increasing proportionally—and demonstrated that ELISA optical density could reasonably predict infection intensity, though individual animal readings showed considerable variation. Whilst high variation limits the diagnostic utility of ELISA for identifying infection status in single animals, group-level testing of yard populations could provide practitioners with reliable indicators of overall parasite exposure and burden. For equine professionals managing multiple horses, this suggests serological screening of cohorts offers a practical approach to identifying premises requiring targeted anthelmintic intervention, particularly where post-mortem confirmation is unavailable.
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Practical Takeaways
- •Tapeworm infection is a significant parasitic burden in UK horses; practitioners should consider A. perfoliata as a common finding in equine populations
- •Individual ELISA results should be interpreted cautiously, but testing groups of horses can reliably indicate herd infection status for management decisions
- •Knowledge of density-dependent worm weight relationships may inform understanding of clinical significance at different infection intensities
Key Findings
- •Anoplocephala perfoliata was the most abundant parasitic species found in stomach and small intestine of 118 slaughtered horses
- •Tapeworm total weight increased with number of worms but showed density-dependent constraints on maximum weight
- •ELISA antibody testing could approximately predict A. perfoliata burden, though individual animal variation was wide
- •Group-level ELISA testing provided useful reflection of overall infection levels despite limitations in individual animal diagnosis