To add support to the concept of a cycle of silent EHV-1 infection. To show the amount of antibody passed on to foals in colostrum and how long this antibody level lasts in foals. The researchers will conduct a cohort study of foals born in September on a number of stud farms. Nasal swabs and blood samples will be collected from these foals and their dams from mid-November to late December and for 4 weeks after they are weaned. They will evaluate the usefulness of the currently available vaccine for prevention of infection of young horses and for protection of mares from possible EHV-1 abortion.
Respiratory disease is an important cause of wastage in the horse racing industry.
Equine herpesvirus type 5 has been recognised only recently and its potential contribution to respiratory disease in horses has not been evaluated. The clinical significance of this observation is not known at this stage. The relationship between reactivation of herpesviral infection and antibody status or cellular immunity is poorly defined, especially in the horse. To determine factors that affect the activation of latent virus infections, and whether activation of latent virus infections contributes to the development of respiratory disease or decreased performance. To provide evidence that some strains of EHV-2 are causes of respiratory disease, perhaps acting as stressors activating other latent herpesvirus.