Efficacy Testing: EquiStatus™ Tapeworm Process
Reduced effectiveness of anti-tapeworm anthelmintics has been detected in the UK. As part of our recent research, four stud farms were found to have anti-tapeworm treatment failure using the EquiStatus™ approach (see details in our Technical Document).
EquiStatus™ Tapeworm provides a research-backed structured approach to establishing group tapeworm infection status, identifying where treatment effectiveness investigation is needed, guiding treatments, management and ongoing monitoring.
The EquiStatus™ Tapeworm Service
Antibody screening is essential to first establish a group’s tapeworm infection profile. Faecal egg counts (FECs) cannot reliably rule out infection so are unsuitable in a screening phase.
EquiStatus™ Flotation FEC testing is used selectively to investigate treatment effectiveness in groups where high infection levels in most horses, together with the group’s history, indicate that further investigation is warranted. FEC testing in these groups is more likely to generate meaningful results. Full guidelines are available to support the use of EquiStatus™ Tapeworm in line with research evidence underpinning the approach. The accompanying Technical Document provides a detailed account of the supporting literature, research and analysis (peer reviewed publication in preparation).
1. Screen - establish group tapeworm infection status
Use saliva or blood antibody screening first to establish the group’s tapeworm infection profile.
Testing should be performed a minimum of 3 months for saliva testing and 6 months for blood testing after the last anthelmintic treatment.
FEC testing is unsuitable for initial screening because of a high likelihood of false negative results due to low and intermittent tapeworm egg shedding in most groups of horses.
Free interpretation support available
2. Interpret - determine if efficacy investigation is needed
Interpret the antibody results profile alongside the group’s treatment, clinical and management history.
Low antibody results or low prevalence of infection support the likelihood that current tapeworm control measures are effective.
High/off-scale or persistently elevated antibody results in most or all horses, together with an indicative management and/or clinical history, suggest that further investigation into anthelmintic effectiveness is warranted.
Relevant history may include repeated treatment with the same anthelmintic, clinical signs consistent with tapeworm infection or persistently high antibody levels despite treatment. Free interpretation support is available.
3. Investigate - assess efficacy using the EquiStatus™ Flotation FEC test
For groups requiring further investigation, use EquiStatus™ Flotation FEC testing: a validated FEC method for assessing tapeworm egg counts before and after anthelmintic treatment.
Day 0 - before tapeworm treatment
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If few or no eggs are detected: do not resample at Day 14. Instead, routinely monitor by antibody testing, combined with management improvements to reduce tapeworm transmission. If the antibody profile does not change, or worsens over time, repeat EquiStatus™ Flotation FEC testing.
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If eggs are detected: repeat the flotation FEC test at Day 14 after treatment.
Day 14 - after treatment
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No eggs detected in most horses is suggestive of treatment success. Some horses may have false negative results due to inconsistent egg shedding.
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Detection of eggs in most horses is consistent with reduced effectiveness of treatment.When considering very small groups of horses or individuals, investigation must be supported by historic antibody test results and treatments. Consider repeating the EquiStatus™ Flotation FEC test on sequential samples obtained over a series of days to reduce the impact of inconsistent egg excretion when horse numbers are low.
Free advice available
4. Act - respond to the findings
Use all available evidence to guide further tapeworm treatment decisions and management.
If treatment appears effective:
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Review and improve management to reduce tapeworm transmission.
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Minimise unnecessary or repeated treatments to protect anthelmintic effectiveness.
If reduced efficacy is identified:
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Immediately review and revise the parasite control plan under veterinary supervision and report to the Veterinary Medicines Directorate.
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Take immediate, significant steps to reduce tapeworm transmission, including improving paddock hygiene and, where appropriate, moving horses to clean grazing or stabling.
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Consider an alternative licensed treatment and investigate effectiveness.
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Avoid repeated use of an ineffective treatment.
5. Monitor - track infection status over time
Combine risk assessments using www.whatsyourwormrisk.com with antibody testing to track infection status.
Regularly review and revise management practices where necessary to reduce tapeworm transmission. Re-test antibody levels in saliva and blood at appropriate intervals following treatments.
Compare results over time to assess the response to treatment and management changes:
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If antibody levels are reducing: continue the current approach and keep monitoring.
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If antibody levels remain persistently elevated or increase despite management improvements and targeted treatments: investigate anthelmintic efficacy with EquiStatus™ Flotation FEC testing.
Only investigate where the evidence indicates:
The role of the EquiStatus™ Flotation FEC test
Not a replacement for antibody screening
Faecal methods have poor sensitivity for screening. Tapeworm eggs are shed intermittently from adult parasites and many infections comprise high proportions of non-egg shedding worms. A negative FEC cannot reliably rule out tapeworm infection.
A targeted investigation tool
The value of EquiStatus™ Flotation testing comes from use in appropriate groups of horses after antibody screening indicates high infection levels are present in most horses in the group.
No unnecessary testing
EquiStatus™ offers a cost-effective, targeted approach to guide testing, treatment and management decisions, with efficacy testing focused on groups where it is most likely to provide useful results.
Supporting documents