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sensitivity is comparable between egg types. However, Wisconsin and McMaster were recently found to perform with very similar diagnostic sensitivities for detection of strongyle eggs (Cain et al., 2020), so it is possible that qualitative performance would also be similar for detection of ascarid eggs between these two techniques.
Take home messages
Based on the items covered herein, equine veterinarians making use of faecal egg counts should consider the following take-home points:
• Routine testing anthelmintic treatment efficacy is of paramount importance in equine veterinary practice of
today and should be the starting point for any parasite control program.
• In foals, weanlings and yearlings, faecal egg counts should be used to monitor presence of ascarid parasites
to allow selection of appropriate anthelmintics.
• In mature horses, strongylid faecal egg counts can be used to classify horses into low, moderate and high
shedders for a tailored parasite control approach targeting cyathostomin parasites.
• Faecal egg counts are neither indicative of worm burden size nor parasitic involvement in clinical disease.
• Themultiplication factor of a faecal egg counting technique is not synonymouswith its diagnostic or analytic sensitivity.
• Diagnostic sensitivity and specificity have limited implications for the performance of faecal egg counting techniques.
• Accuracy and precision are important quantitative performance parameters for faecal egg counting
techniques, but they are not synonymous.
• Precision has the largest implications for faecal egg counts given the estimation of anthelmintic efficacy and
classification of strongylid egg shedding status.
• Training and experience of personnel performing faecal egg counts affects test performance and needs attention.
• Automated faecal egg counting techniques perform with higher precision than manual techniques and will likely
become more widely used in the future. Author’s declaration of interests
The author holds stock in MEP Equine Solutions, LLC, which is commercialising an automated image-based parasite egg counting technology.
Ethical animal research Ethical review not applicable for this review article.
Source of funding This article was not financially supported.
References
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