Shedding consistency of strongyle-type eggs in Dutch boarding horses.

This study observes the variation in the number of strongyle-type eggs found in the feces of Dutch boarding horses. The research finds that some horses have consistently low egg counts and this could potentially inform strategies for targeted antiparasitic treatment to reduce development of resistance.

Methodology

• A total of 484 Dutch boarding horses were examined in this study.
• Each horse’s feces were sampled twice within a 6-week interval while anthelmintic (anti-parasitic) treatment was temporarily halted.
• The faecal egg counts (FECs) – the number of eggs per gram of feces (EPGs) – were then measured and categorized as ‘consistently low’ (less than or equal to 100 EPGs) and ‘consistently high’ (more than 100 EPGs).

Findings

• More than half the horses examined, 267 out of 484 (55.2%), presented consistently low EPGs.
• Around a third of the horses, 155 out of 484 (32.0%), had consistently high FECs.
• Horses with high EPGs were commonly mares with frequent pasture access, less than 6 years or more than 23 years old, dewormed less frequently (beyond 6 months intervals), and had last been treated over 3 months prior.
• Alternatively, horses with lower EPGs were often males with limited or no pasture access, dewormed every 6 months, and aged between 6 and 23 years.

Implications

• The study’s findings hint at the possibility that some horses constantly exhibit low FECs, raising the potential for these horses to be nontreated in selective anti-parasitic treatment programs.
• This approach would aim to prevent overuse of anthelmintic treatments and consequently, reduce the risk of parasites developing resistance against these treatments.