Severely Asthmatic Horses Residing in a Mediterranean Climate Shed a Significantly Lower Number of Parasite Eggs Compared to Healthy Farm Mates.
Authors: Simões Joana, Sales Luís José Paulo, Madeira de Carvalho Luís, Tilley Paula
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Researchers have long suspected an inverse relationship between parasitic infections and allergic airway disease in horses, prompting a Mediterranean-based investigation into whether severely asthmatic horses might exhibit reduced helminth burdens compared with their clinically healthy herd mates. Faecal samples from asthmatic and healthy horses on identical farms (sharing identical deworming protocols and environmental exposure) were analysed both qualitatively and quantitatively for parasite eggs and larvae, with strongyles and Cyathostomum sensu latum identified as the predominant species across both groups. The critical finding was a statistically significant reduction in faecal egg count (FEC) and infective larvae count in the severe equine asthma (SEA) group relative to healthy controls—suggesting an intrinsic immunological resistance to gastrointestinal helminths in asthmatic individuals rather than merely different environmental exposure or management practices. This apparent protective mechanism warrants investigation of the underlying immune responses, as understanding whether T helper cell polarisation toward Th2-dominant asthmatic pathways confers parasite resistance could reshape our current deworming strategies and inform clinical decision-making around anthelmintic frequency. Whilst this Mediterranean cohort mirrors findings from previous European research, larger-scale studies are needed to establish whether this phenomenon is a consistent feature of equine asthma or influenced by climate, breed predisposition, or other confounding variables.
Read the full abstract on PubMed
Practical Takeaways
- •Severely asthmatic horses may have a natural resistance to helminth infections, suggesting their immune dysregulation in respiratory disease may confer protection against gastrointestinal parasites
- •Standard deworming protocols should continue regardless of asthma status, as this study shows asthmatic horses still harbor parasites despite lower shedding rates
- •Consider investigating the immunological mechanisms underlying reduced parasite burdens in asthmatic horses, as this may reveal novel insights into both allergic disease and parasite resistance
Key Findings
- •Severely asthmatic horses shed significantly fewer parasite eggs and infective larvae per gram of feces compared to healthy farm mates despite identical environmental and deworming management
- •Strongyle-type eggs and Cyathostomum sensu latum larvae were the most abundant parasites in the studied population with no significant differences in parasite types between asthmatic and healthy groups
- •The reduced parasite egg shedding in severely asthmatic horses may indicate an intrinsic resistance to gastrointestinal helminths