Prevalence and Risk Factors Associated With Natural Infection by Trypanosoma evansi in Campeiro Horses

Area of Science:

• Veterinary Parasitology
• Equine Health
• Epidemiology

Background:

• The Campeiro horse, a locally adapted breed in Southern Brazil, is critically endangered.
• Surra, caused by Trypanosoma evansi, affects horses but its prevalence in Campeiro horses is unknown.
• Preservation efforts for this unique genetic resource are essential.

Purpose of the Study:

• Determine the prevalence of Trypanosoma evansi infection in Campeiro horses.
• Correlate hematological and serum biochemical parameters with infection status.
• Identify potential risk factors associated with T. evansi infection.

Main Methods:

• Collected blood samples from 214 Campeiro horses across three Brazilian states.
• Utilized polymerase chain reaction (PCR) and immunofluorescence antibody test (IFAT) for T. evansi detection.
• Conducted complete blood counts, serum biochemistry, and owner epidemiological questionnaires.

Main Results:

• Prevalence of T. evansi was 14% by PCR and 59% by IFAT.
• Infected horses showed altered hematological values (increased hematocrit, basophils) and biochemical markers (decreased fibrinogen, ALT, AST, urea; increased CPK, creatinine), though likely unrelated to infection.
• No significant risk factors were identified through questionnaires.

Conclusions:

• Trypanosoma evansi is present in Southern Brazil with a high prevalence in the endangered Campeiro horse breed.
• Further research is needed to understand the clinical significance of these biochemical and hematological changes in infected horses.
• Monitoring and control strategies are crucial for the conservation of Campeiro horses against T. evansi.