Welfare assessment of Thoroughbred horses naturally infected with gastrointestinal parasites in Southern Brazil: Quantifying the host-parasite relationship.
Authors: Pires L S Abrahão, Abrahão C, Dias de Castro L L, Hammerschmidt J, Antunes J, Molento C F M, Molento M B
Journal: Journal of equine veterinary science
Summary
Gastrointestinal parasite burdens are routinely monitored in equine practice through faecal egg counts, yet their direct relationship to individual horse welfare remains poorly characterised. Brazilian researchers assessed welfare indicators and parasitic infection in 90 Thoroughbreds (mares and two foal cohorts) over 12 months, conducting 1,024 standardised evaluations across five trained assessors to correlate faecal egg counts with behavioural and physical condition markers. Despite egg counts ranging from zero to 5,760 (with small strongyles dominant in 98.8% of samples), no significant association emerged between parasite burden and welfare indicators; 94.4% of horses maintained ideal body condition and 95.8% displayed good clinical and behavioural health throughout the study period. These findings suggest that faecal egg count alone is an insufficient predictor of compromise to horse welfare when animals receive adequate nutrition and routine health management. For practitioners, this underscores the importance of contextualising parasitology results within broader welfare assessments rather than treating elevated egg counts as automatic indicators of clinical concern requiring intervention.
Read the full abstract on PubMed
Practical Takeaways
- •Parasite fecal egg count alone should not be used to judge horse welfare when nutrition and health management are adequate—focus on actual observable welfare signs instead
- •Routine parasite monitoring remains important, but normal FEC does not necessarily indicate welfare compromise if horses maintain good body condition, clinical health, and behavior
- •Integrate parasite infection status into holistic welfare assessments that also consider body condition, nutrition, and clinical signs rather than relying on FEC as a standalone welfare indicator
Key Findings
- •FEC ranged from 0 to 5,760 eggs with 98.8% of horses shedding small strongyle eggs, yet no significant association was found between FEC and behavioral welfare indicators
- •94.4% of evaluations (n=967) showed ideal body condition scores and 95.8% of all horses had good clinical and behavioral indicators despite parasite infection
- •Good nutritional and health management practices maintained welfare indicators independent of fecal egg count variation over 12 months of monitoring