Effects of Competitive ELISA-Positive Results of Piroplasmosis on the Performance of Endurance Horses.
Authors: Bravo-Barriga Daniel, Serrano-Aguilera Francisco J, Barrasa-Rita Rafael, Habela Miguel Ángel, Chacón Rafael Barrera, Ezquerra Luis Javier, Martín-Cuervo María
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Equine Piroplasmosis and Endurance Performance Asymptomatic carriers of equine piroplasmosis (EP) are commonplace in southern European endurance populations, yet little was known about whether subclinical infection compromises competitive performance—a gap this Spanish study addressed by recruiting 40 elite endurance horses across national competitions in Extremadura. Researchers collected blood samples before and after races, measuring haematological and biochemical parameters alongside EP seroprevalence using competitive ELISA, with 70% of the cohort testing positive (predominantly *Theileria equi* at 67.5%, with smaller numbers of *Babesia caballi* or dual infection). Remarkably, seropositivity showed no measurable effect on completion rates, finishing position or performance outcomes, nor did clinically silent carriers exhibit significant differences in routine blood work compared to seronegative horses—suggesting that subclinical piroplasmosis does not impair competitive capacity in endurance events up to 80 km. These findings provide evidence-based reassurance for competition organisers and participants, though practitioners should note this represents a single-distance snapshot and longer formats require evaluation before firm recommendations can be established. The high prevalence of asymptomatic infection in this population underscores the limited practical utility of routine screening in endemic regions where performance remains unaffected.
Read the full abstract on PubMed
Practical Takeaways
- •Endurance horses testing seropositive for equine piroplasmosis without clinical signs can safely compete in races up to 80 km without expected performance penalties
- •Veterinarians and competition organizers should consider that high prevalence of subclinical EP in southern Europe does not justify blanket exclusion of seropositive horses from competition
- •Longer distance competitions (>80 km) require further evaluation before making recommendations about seropositive horse participation
Key Findings
- •Global seroprevalence of equine piroplasmosis was 70% (27/40 horses positive for Theileria equi, 3/40 for Babesia caballi)
- •82.5% of horses (33/40) completed endurance competitions up to 80 km with no significant performance differences between seropositive and seronegative horses
- •No significant differences in hematological or biochemical parameters between EP-seropositive and seronegative horses
- •Asymptomatic EP-positive horses showed no performance impairment in elite national endurance competitions up to 80 km distance