In horse populations with endemic EHV-3, where occasional reactivations of latent virus with shedding by latently infected carriers is undetectable and therefore unavoidable, early diagnosis and containment of spread of infection is most important. Staff involved with stallion mating management should be trained in the recognition of genital skin lesions characteristic of ECE and what to do should signs be suspected.
When infection is suspected or diagnosed in a stallion, mating should cease until the stallion is confirmed free of disease (see below). This usually takes 10-14 days but may take longer in individual stallions. Although, in stallions with no systemic signs of illness, it may be tempting for managers of busy commercial stallions, with the encouragement of some mare owners, to continue to mate mares, this is inadvisable. This is because the stallion may become sore and unwilling to mate/ejaculate and the potential for development of systemic signs of illness and secondary complications will be increased. In addition, this is likely to slow the stallion’s healing and recovery process, will increase the numbers of mares infected and as such will inevitably increase the numbers of latently infected carriers in the horse population.
When infection is diagnosed in a stallion, all owners with mares mated to that stallion should be informed so that they may ask their attending veterinary surgeon to examine their mares for signs of infection. Mare owners should be warned of the delay that is anticipated before the stallion will be available for mating again.
When infection is diagnosed in a mare that has been mated within 3 weeks, the mating stallion owner/manager should be informed so that he/she may cease mating with the stallion and ask the attending veterinary surgeon to examine the stallion for signs of infection. The stallion owner/manager should then notify owners/managers of other mares mated by that stallion within the previous 3-4 weeks so that their veterinary surgeons may examine for signs of infection. Mating should only recommence when the stallion is free from signs of infection; when reports reveal no signs of infections in other mares that he has mated; and veterinary opinion is that he is not in the stage of incubating the infection.
Whilst ECE should be avoidable by the careful use of artificial insemination (AI) (where allowed by registration authorities) with effective barrier management, the potential for virus spread during AI has not been explored.
EHV-3 is quickly destroyed in the environment by lipid solvents, detergents, heat, drying and commonly-used disinfectants. Hygienic management of mare examination stocks and handling areas, particularly at covering barns, is important in the prevention of ECE and other sexually-transmitted diseases.