Nemabiome sequencing reveals seasonal and age associated patterns of strongyle infection and high prevalence of Strongylus vulgaris in Alberta feral horses.
Abstract: Unmanaged feral horses, naïve to dewormers, offer a unique opportunity to study natural communities of equine parasites. These communities may include parasites that are rare in managed populations, and these may be transmitted to domestic horses in areas where there is contact between feral and domestic equine populations. There have been only a few studies of gastrointestinal parasite populations in horses, and very few from North American equine populations. This study aimed to gain insights into parasite biology through identification of the strongyle parasite species infecting feral horses in Alberta, Canada, and to test for species-specific infection patterns across season and horse age. Fecal samples (N = 149) were collected from unique individuals in the Sundre Equine Management Zone (EMZ), Alberta, across two years: 2021 (N = 62) and 2022 (N = 87). In 2021, samples were collected in summer (N = 31; 8 foals, 5 subadults, 18 adults) and fall (N = 31; 5 foals, 1 subadult, 25 adults). In 2022, samples were collected in spring (N = 36; 4 subadults, 32 adults), summer (N = 41; 4 foals, 8 subadults, 29 adults), and fall (N = 20; 1 foal, 2 subadults, 17 adults). Fecal egg counts showed that these horses shed high numbers of strongyle eggs relative to domestic horse populations (mean = 1337.01 ± 961.81 epg), and nemabiome analyses identified a total of 34 strongyle species. Species richness and aggregate strongyle FECs were highest in subadults and during the summer, while lowest in foals and during the fall. There was a high prevalence of large strongyle species, especially (85.91 %), with strongyle species-specific prevalence and FECs strongly associated with age and season. Understanding the factors driving species-specific parasite infection provides important information on strongyle parasite ecology and may aid the development of targeted parasite control strategies.
© 2025 The Authors.
Publication Date: 2025-05-28 PubMed ID: 40524829PubMed Central: PMC12167826DOI: 10.1016/j.ijppaw.2025.101091Google Scholar: Lookup
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Summary
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This study delves into the high prevalence of strongyle parasite species, notably Strongylus vulgaris, in Alberta’s feral horse populations. Researchers identified species-specific infection patterns grounded in season and horse age, thus facilitating an improved understanding of strongyle parasite ecology, which may prove beneficial for formulating targeted parasite control schemes.
Study Background
- Feral horses, devoid of dewormer treatment, provide a unique opportunity for investigating the natural community of equine parasites. This study aims to scrutinize the various species of strongyle parasites infecting feral horses in Alberta, Canada. Such an analysis allows for subsequent detection of species-specific infection patterns based on season and horse age.
- Despite the rarity of gastrointestinal parasite studies in horses, and particularly in North American equine populations, an understanding of these parasites is important because they may be transferred to domestic horse populations, particularly in regions where feral and domestic populations interact.
Data Collection and Findings
- Over two years—2021 and 2022— fecal samples were collected from unique individuals in the Sundre Equine Management Zone in Alberta. The samples were gathered at different times of the year (spring, summer, and fall) and from horses of varying ages (foals, subadults, and adults).
- Fecal egg count measurements showed that these horses shed high numbers of strongyle eggs relative to domestic horse populations. In total, researchers identified 34 distinct strongyle species through nemabiome analysis.
- In terms of species richness and strongyle fecal egg counts, the results were highest in subadults and during the summer seasons. Conversely, the results were lowest in foals and during the fall seasons.
Implications of the Study
- The study established a high prevalence of large strongyle species, specifically Strongylus vulgaris (85.91 %). The prevalence and fecal egg counts of strongyle species were strongly associated with the age and season, indicating a season and age specific mechanism of infection.
- Understanding the factors that drive species-specific parasite infections can provide significant information on strongyle parasite ecology. Such knowledge can be essential for developing targeted parasite control strategies, protecting both feral and domestic horse populations.
Cite This Article
APA
Ochigbo GO, Ahn S, Belhumeur KA, Poissant J, Rosa BV.
(2025).
Nemabiome sequencing reveals seasonal and age associated patterns of strongyle infection and high prevalence of Strongylus vulgaris in Alberta feral horses.
Int J Parasitol Parasites Wildl, 27, 101091.
https://doi.org/10.1016/j.ijppaw.2025.101091 Publication
Researcher Affiliations
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
- Faculty of Science, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
- Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
Conflict of Interest Statement
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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