Gastrointestinal Parasitism in Miranda Donkeys: Epidemiology and Selective Control of Strongyles Infection in the Northeast of Portugal.
Authors: Ramalho Sousa Sérgio, Anastácio Sofia, Nóvoa Miguel, Paz-Silva Adolfo, Madeira de Carvalho Luís Manuel
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Donkey populations in northeast Portugal have received little parasitological attention despite their ecological and agricultural significance, prompting researchers to characterise gastrointestinal strongyle infection in 62 Miranda donkeys over five years and evaluate targeted selective treatment (TST) as an alternative to blanket deworming protocols. Rather than routine six-monthly anthelmintic administration, the study progressively implemented a faecal egg count (FEC)-based approach, treating animals only when egg shedding exceeded 500 EPG alongside quarterly parasitological monitoring. Annual strongyle prevalence declined substantially from 35.5% to 19.4%, with younger animals (under four years) and those in poor body condition showing higher infection rates (46.7% and 40.8% respectively), whilst seasonal variation peaked in June and reached nadir in December. Cyathostomum sensu lato dominated the parasite community with Strongylus vulgaris as the principal large strongyle, though concerning monodominance of Cyathostominae emerged by study end, highlighting the adaptive capacity of small strongyles to selective pressure. For equine professionals managing donkeys on pasture, these findings support the adoption of evidence-based FEC monitoring with selective treatment protocols—reducing unnecessary anthelmintic use whilst maintaining efficacy—yet emphasise the critical importance of continued faecal surveillance to detect emerging resistance patterns and shifting parasite populations.
Read the full abstract on PubMed
Practical Takeaways
- •Targeted selective treatment based on EPG thresholds (≥500 EPG trigger deworming) is an effective and rational alternative to routine strategic deworming in donkey populations, reducing treatment frequency while lowering prevalence
- •Young donkeys (<4 years), females, and animals with poor body condition require closer parasitological monitoring as they carry higher infection burdens and egg shedding
- •Maintain regular quarterly fecal monitoring indefinitely, as loss of parasite biodiversity (Cyathostominae dominance) poses long-term resistance risk; seasonal patterns (peaks in June, lows in December) should inform monitoring schedules
Key Findings
- •Annual prevalence of strongyle infection decreased from 35.5% to 19.4% over five years with targeted selective treatment (TST) approach
- •Prevalence was significantly higher in females (39.5%), animals under 4 years (46.7%), and those with lower body condition (40.8%)
- •Egg output peaked in June (highest EPG) and was lowest in December, with younger animals (<4 years) shedding more eggs (589.3 EPG) than those older than 10 years (533.6 EPG)
- •Cyathostomum sensu lato was the most prevalent genus; by study end, Cyathostominae were the only isolated strongyles, indicating reduced parasite biodiversity