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behaviour
nutrition
riding science
2020
Cohort Study

Gastrointestinal Strongyles Egg Excretion in Relation to Age, Gender, and Management of Horses in Italy.

Authors: Scala Antonio, Tamponi Claudia, Sanna Giuliana, Predieri Giulio, Dessì Giorgia, Sedda Giampietro, Buono Francesco, Cappai Maria Grazia, Veneziano Vincenzo, Varcasia Antonio

Journal: Animals : an open access journal from MDPI

Summary

# Gastrointestinal Strongyles in Italian Horses: Distribution Patterns and Management Implications Strongyle parasitism remains a significant concern in equine populations, with emerging anthelmintic resistance necessitating evidence-based control strategies informed by local epidemiological data. This Italian study examined faecal egg counts (FEC) and coproculture results from 39.5% of surveyed horses, identifying risk factors through analysis of age, sex, management system, geographical location and breed to inform targeted intervention protocols. A striking 80% of total egg shedding originated from just 12.8% of positive horses, predominantly small strongyles rather than the more pathogenic large strongyle species, with mean EPG of 245 across infected animals and 86.4% of stables harbouring at least one positive individual. Anthelmintic-treated horses showed significantly reduced EPG, with macrocyclic lactones proving most effective, whilst seasonal variation, management intensity, breed predisposition and sex-based differences all emerged as significant epidemiological factors. These findings support the shift towards targeted, diagnostic-driven treatment protocols rather than blanket chemotherapy, emphasising the critical role of regular faecal monitoring in identifying high-shedder individuals and timing interventions strategically to reduce both parasite burden and selection pressure for resistance.

Read the full abstract on PubMed

Practical Takeaways

  • Use targeted treatment strategies focusing on the small percentage of heavy shedders rather than treating all horses equally; requires regular fecal testing to identify these individuals
  • Macrocyclic lactone anthelmintics remain effective for strongyle control in Italy, but continued surveillance is essential to monitor for resistance development
  • Implement seasonal and management-based parasite control protocols, as prevalence varies significantly by season, management system, and geographical location

Key Findings

  • 86.4% of stables had at least one horse positive for strongyle egg shedding with 39.5% overall prevalence and mean EPG of 245
  • 80% of total EPG was shed from only 12.8% of positive horses, indicating clustered egg excretion in a small proportion of animals
  • Macrocyclic lactones (MLs) were the most effective anthelmintic class, resulting in significantly lower EPG values compared to untreated horses
  • Small strongyles were the predominant parasite burden in Italian horses despite large strongyles being more pathogenic

Conditions Studied

gastrointestinal strongyle infectionsmall strongyleslarge strongyles