Equine Arteritis Virus (EAV) Outbreak in a Show Stallion Population.

Area of Science:

• Veterinary Virology
• Equine Infectious Diseases
• Animal Reproduction

Background:

• Equine arteritis virus (EAV) causes significant reproductive losses and vasculitis in horses.
• Intact stallions act as chronic reservoirs for EAV due to persistent infection of accessory sex glands.
• Infected semen is a primary recognized source of EAV transmission.

Purpose of the Study:

• To describe the acute EAV infection and transmission dynamics within a stallion population.
• To investigate the spread of EAV following the introduction of new stallions.
• To identify the primary routes of EAV transmission in an outbreak scenario.

Main Methods:

• Monitoring clinical signs in a stallion population.
• Detecting EAV antigen using PCR on nasal swabs and EDTA blood samples.
• Assessing seroconversion in affected animals.

Main Results:

• Acute clinical signs of EAV infection were observed in the stallion group.
• EAV antigen was detected in nasal swabs and blood during the acute phase.
• Serological evidence of infection (seroconversion) was confirmed.

Conclusions:

• EAV transmission occurred via respiratory routes, potentially initiated by seminal fluid exposure.
• The study confirms horizontal transmission of EAV through the respiratory tract.
• Respiratory transmission should be considered in EAV-persistent herds, especially when introducing new animals.