Parasite Occurrence and Parasite Management in Swedish Horses Presenting with Gastrointestinal Disease-A Case-Control Study.
Authors: Hedberg-Alm Ylva, Penell Johanna, Riihimäki Miia, Osterman-Lind Eva, Nielsen Martin K, Tydén Eva
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Parasite Management and Gastrointestinal Disease in Swedish Horses Swedish equine practitioners are facing a growing challenge with intestinal parasites—particularly *Strongylus vulgaris*—since prescription-only anthelmintic regulations were introduced roughly a decade ago. Researchers conducted a prospective case-control study comparing parasitological status between horses presenting with gastrointestinal disease and healthy controls at a university hospital over 12 months, using fecal egg counts (FEC), PCR testing for *S. vulgaris* DNA, serology, and owner questionnaires on deworming and pasture practices. Whilst only 5.5% of horses tested positive for *S. vulgaris* by PCR, 62% showed positive antibody titres on ELISA—with significantly elevated antibody levels evident in horses diagnosed with peritonitis—indicating substantial exposure to the parasite despite low active infection detection. Current management practices were fragmented: just 36% of owners relied on FEC alone, 32% combined FEC with targeted diagnostics for *S. vulgaris* or *Anoplocephala perfoliata*, and 29% continued routine deworming without any diagnostic testing, whilst effective pasture management strategies remained uncommon. The findings underscore an urgent need for practitioner education in tailored diagnostic protocols and evidence-based pasture management, particularly given the apparent high exposure risk and the shift towards targeted rather than blanket anthelmintic strategies.
Read the full abstract on PubMed
Practical Takeaways
- •Implement fecal egg count testing and specific S. vulgaris diagnostics (PCR and serology) as standard practice rather than routine deworming; high seropositivity suggests widespread exposure that needs targeted management
- •Consider S. vulgaris as a differential diagnosis in horses with peritonitis, particularly given rising concerns about this parasite in Sweden since prescription-only anthelmintics were implemented
- •Educate clients on pasture management strategies to reduce parasitic burden, as this appears to be a significant knowledge gap; rotation systems and fecal monitoring should be prioritized over blanket deworming protocols
Key Findings
- •S. vulgaris PCR prevalence was 5.5%, but 62% of horses tested positive on ELISA serology, indicating high exposure despite low active infection rates
- •Horses presenting with peritonitis showed significantly higher S. vulgaris antibody levels compared to other diagnoses and control horses
- •Only 36% of horse owners used fecal egg counts alone for parasite management, while 29% dewormed routinely without prior diagnostics
- •Effective pasture management methods to reduce parasitic burden were rare among surveyed horse owners