Selective Anthelmintic Treatment in Horses in Sweden Based on Coprological Analyses: Ten-Year Results.
Authors: Osterman-Lind Eva, Holmberg Mia, Grandi Giulio
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Selective Anthelmintic Treatment in Horses in Sweden Between 2008 and 2017, the Swedish National Veterinary Institute analysed 43,330 faecal samples from over 26,600 horses across 935 premises, using quantitative flotation and larval culture or PCR to identify strongyles, tapeworms, ascarids and specifically *Strongylus vulgaris*. The prevalence data revealed that 4–11% of individual horses tested positive for *S. vulgaris* and 3–10% shed tapeworm eggs, with the researchers identifying recurrent patterns of high and low egg shedders within herds; notably, three-quarters of *S. vulgaris*-positive horses appeared to be recent introductions to their premises. Based on strongyle egg-shedding levels and *S. vulgaris* status, 59% of tested horses required no deworming treatment, demonstrating that selective anthelmintic protocols—guided by coprological evidence rather than blanket dosing—can substantially reduce unnecessary drug exposure whilst maintaining parasite control. These findings underscore the importance of premise-specific faecal testing and targeted treatment recommendations to slow anthelmintic resistance development, suggesting that equine professionals should advocate for diagnostic-led deworming strategies and heightened biosecurity around newly arrived horses, particularly given the high proportion of *S. vulgaris* cases linked to herd introductions.
Read the full abstract on PubMed
Practical Takeaways
- •Selective deworming based on faecal egg counts and S. vulgaris testing can reduce unnecessary anthelmintic use by ~60%, helping preserve drug efficacy and slow resistance development
- •Focus quarantine and testing protocols on newly introduced horses, as 75% of S. vulgaris cases involved recent additions to herds
- •Implement premise-specific parasite management strategies rather than blanket deworming; individual faecal sampling is more sensitive than pooled samples for detecting S. vulgaris
Key Findings
- •Between 4-11% of individual horses tested positive for Strongylus vulgaris over the 10-year monitoring period (2008-2017)
- •3-10% of horses were shedding tapeworm eggs, with recurrent patterns of high and low shedders identified
- •59% of horses did not require deworming based on selective treatment protocols using coprological analysis and S. vulgaris diagnostics
- •75% of S. vulgaris-positive horses appeared to have been recently introduced into herds, indicating epidemiological significance of new arrivals