Decreased Virus-Neutralizing Antibodies Against Equine Herpesvirus type 1 In Nasal Secretions of Horses After 12-hour Transportation.

This research article studied the impacts of long-distance transportation on horse’s immune response to certain types of equine herpesvirus (EHV-1 and EHV-4). It found that transportation stress may suppress horses’ ability to neutralize the EHV-1 virus, making them more susceptible to infection.

Objective and Methodology

• The research aimed to understand the impacts of long-distance (12 hours) transportation on horse’s immune responses to equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4).
• Six healthy thoroughbred horses with previous transport experience were used in the study. They were transported in commercial trucks, recreating the same three-hour route four times to mimic a 12-hour trip.
• The researchers conducted tests including real-time PCR analysis of nasal swabs and peripheral blood mononuclear cells (PBMCs) to monitor potential replication of EHV-1 and EHV-4. They also observed changes in systemic and mucosal antibodies.
• Cortisol measurements from blood samples were taken regularly to monitor stress levels of the horses. Other samples from nasal swabs, PBMCs, nasal washes and sera were collected at different intervals.

Findings

• The study confirmed that transportation does induce acute stress in horses, which was evidenced by the significant increase in cortisol concentration after three and six hours of transport.
• There was no detectable viral replication or lytic infection of EHV-1 and EHV-4. Serum virus neutralization (VN) titers for these viruses were also largely unchanged. An exception was one horse that had a four-fold decrease in its ability to neutralize EHV-1 after transportation.
• Researchers observed significant increases in urea and total IgA concentration in nasal washes after transportation, suggesting a stress response. However, the total IgA/protein ratio remained unchanged.
• The research also discovered a temporary decrease in VN titers for EHV-1 in nasal wash concentrates in four out of the six horses, suggesting suppression of the mucosal immune response to EHV-1 after transportation.
• This suggests that the stress of transportation can potentially make horses more susceptible to EHV-1 infections. VN antibodies against EHV-4 in nasal secretion were not detected at any timepoint.

Conclusions

• Overall, these findings indicate that long-distance transportation can have an impact on a horse’s immune response, potentially making them more susceptible to EHV-1 infections.
• This may be due to the stress of transport, which can suppress the horse’s capacity to neutralize EHV-1 in the nasal mucosa. However, more research is needed to establish this connection definitively.