Abstract
BackgroundHorses are host to a plethora of parasites. Knowledge of the seasonality of parasite egg shedding and transmission is important for constructing parasite control programs. However, studies describing these patterns are sparse, and have largely been conducted only in the United Kingdom. This study evaluated strongylid egg shedding patterns and transmission dynamics of Strongylus vulgaris in naturally infected and untreated mares and foals through one calendar year in Kentucky, USA. The study also investigated the existence of a peri-parturient rise (PPR) in strongylid egg counts in foaling mares and collected information about Strongyloides westeri and Parascaris spp. in the foals.MethodsThis study was conducted from January to December 2018. A herd of 18 mares, one stallion, and 14 foals born in 2018 were followed throughout the year. Sera and feces were collected biweekly from all horses, and worm burdens enumerated in 13 foals at necropsy. An S. vulgaris ELISA antibody test was run on all serum samples. Fecal egg counts were determined for all horses, and coproculture and qPCR assay were employed to test for the presence of S. vulgaris in the mature horses. Data were analyzed using the proc glimmix procedure in the SAS 9.4 software program.ResultsWe found a general lack of seasonality in strongylid egg shedding throughout the year among the mature horses, and no PPR was demonstrated. Shedding of S. vulgaris eggs displayed a higher abundance during the spring, but findings were variable and not statistically significant. Anti-S. vulgaris antibody concentrations did not display significant fluctuations in the mature horses, but evidence of passive transfer of antibodies to the foals was demonstrated, and foals assumed their own production of antibodies starting at approximately 20 weeks of age. Overall, colts shed higher numbers of strongylid, ascarid, and S. westeri eggs than fillies.ConclusionsThis study demonstrated a lack of seasonality in strongylid egg shedding for the study population, which is in stark contrast to previous studies conducted elsewhere. This strongly suggests that more studies should be done investigating these patterns under different climatic conditions.Graphical
Highlights
Horses are host to a plethora of parasites
There were no statistical associations between mean strongylid fecal egg counts (FECs) and age groups, seasons, collection dates, or parturition status among the mature horses
Foal fecal egg counts Strongylids For strongylid egg shedding, eggs were first detected in the feces at 1 week of age (Fig. 2)
Summary
Knowledge of the seasonality of parasite egg shedding and transmission is important for constructing parasite control programs. Studies describing these patterns are sparse, and have largely been conducted only in the United Kingdom. Frequent anthelmintic treatments administered at regular intervals year-round significantly reduced the prevalence of S. vulgaris, and cyathostomins subsequently became the focus of parasite control [6, 7]. These decades of intense anthelmintic treatment regimens led to widespread drug resistance among cyathostomins [1, 2]. Current recommendations aim to adopt surveillance-based parasite control programs and reduce anthelmintic treatment intensities to delay further resistance development as much as possible [8,9,10]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
