Farm size and biosecurity measures associated with Strongylus vulgaris
infection in horses
Abstract
Background: Selective anthelmintic treatment, advocated due to
evolving anthelmintic resistance, has been associated with an increase
in Strongylus vulgaris prevalence. Reverting to routine interval
anthelmintic treatments is not viable and therefore, identifying other
management factors correlated with S. vulgaris infection is
vital. Objectives: To investigate possible risk factors
associated with the presence of S. vulgaris infection in residing
horses on Swedish horse establishments. Study design:
Internet-based questionnaire survey. Methods: A questionnaire,
created using the internet-based survey platform Netigate, was
distributed to owners of equine establishments throughout Sweden via
established equine platforms and social media channels. The survey was
available for response from May 21 until September 1 2022. Questions
were closed ended with branching logic paths. Results: Four
factors were significantly associated with S. vulgaris infection,
with an increased odds of infection seen in livery yards (OR 1.67, 95%
CI 1.18-2.36, p = 0.004) and premises with more than ten residing horses
(OR 2.42, 95% CI 1.64-3.56, p < 0.001). A lower odds of
infection was seen in establishments using quarantine routines (OR 0.69,
95% CI 0.50-0.96, p = 0.03) and anthelmintic treatment of new horses
prior to arrival at the premise (OR 0.37, 95% CI 0.18-0.74, p = 0.005).
Main limitation: Due to the presence of S. vulgaris
infection in the present study being based on S. vulgaris
diagnostics performed at the farm level, any association between faecal
diagnostic use and risk of infection could not be investigated.
Conclusions: Although the use of diagnostics for S.
vulgaris can keep infection rates low, large farms or livery yards with
many different horse owners, and those with low use of biosecurity
measures as regards to new horses arriving at the premise, are
associated with a higher risk of infection.