Part 1 on this subject discussed the causes, signs and methods of spread of Virus Abortion (EHV)

Is there a vaccine against viral abortion?

  • Yes. Unfortunately Duvaxyn EHV has not been available for the past few months but Pneumobort K vaccine is available.

    • When is the EHV vaccine administered to pregnant mares?

  • The vaccine is give at five, seven and nine months of pregnancy.

    • Does the EHV vaccine produce a complete immunity in vaccinated animals?

  • No, though it is fairly effective and will be very likely to prevent “abortion storms”.

  • Vaccination of all horses raises the level of protection within the population against equine herpes virus.

  • It is recommended that herpes virus vaccine is used for all horses on stud farms to prevent both abortion and respiratory disease caused by EHV.

  • The costs of prevention are likely to be far less than the costs associated with an abortion storm and significantly less than the disruption following a single EHV abortion.

    • Do sales companies require mandatory vaccination against EHV?

  • Not generally. However, during the past year some sales companies have requested that pregnant mares require abortion vaccination.

    • What methods of prevention are recommended?

  • Good hygiene.

  • Vaccination.

  • Keep pregnant mares in small groups.

  • Keep them outdoors as much as possible.

  • If pregnant mares are kept indoors, individual stables are better than big sheds or American Barns as spread of the disease is not as rampant in individual stables.

  • Do not mix performing horses (race horses, fillies out of training, sport horses, hunters), with pregnant mares as they may have mixed with horses that had the respiratory form of the infection at racecourses, shows, etc.

  • Isolate all newcomers away from the remainder of the horses in the yard.

  • Designate separate grooms for broodmares and for the other horses (in training etc).

  • Stallions and colts (especially those that are showjumping and racing), are high risk as they are intermixing every week with horses that may have the respiratory form of the virus.

  • Pregnant mares that arrive from sales or from overseas, should always be considered ‘high risk’ for EHV abortion and should be managed accordingly.

  • Pregnant mares should not be transported with other horses, particularly mares that have aborted recently.

  • A foster mare introduced to the premises should be isolated, particularly from pregnant mares, until it has been proved that EHV did not cause her own foal’s death.

  • Stallions should, wherever possible, be housed in premises separate to the mare operations and should be attended by separate staff, adopting strict biosecurity measures. If it is not possible to have dedicated stallion staff then it is even more important that strict biosecurity measures are adopted to minimise indirect transmission of infection between different horse groups on the stud.

    • What action should be taken in the case of an abortion?

  • The foetus and fluids and membranes should be sent to the laboratory to confirm, or otherwise, the presence of equine herpes virus.

  • This can be carried out on a foetus of a dead foal up to seven days old free of charge at the Irish Equine Centre. This excellent service to the horse industry should be fully availed of under these circumstances.

  • No horse known or suspected to have disease caused by EHV should be sent to a stud or to premises where there are broodmares, particularly pregnant mares.

  • Place the mare and foal in strict isolation.

  • Ensure that the attendant has no contact with other horses, especially with pregnant mares.

  • Cease all horse movements off the premises and do not allow any pregnant mare onto the premises until EHV is excluded as the cause of the abortion, stillbirth, foal death or foal illness.

  • Disinfect and destroy contaminated bedding. The virus is readily destroyed by heat and approved disinfectants. Stables, utensils and transport vehicles should be steam cleaned.

  • Ultra violet light or sunlight is fairly active against the virus.

  • Ensure thorough cleansing and disinfecion of the entire premises, all equipment and vehicles used for horse transport.

    • Is EHV a Notifiable Disease?

  • There are no legal notification requirements for EHV in Ireland although it is advisable to inform the relevant breeders’ association if infection occurs.

  • Because the disease spreads easily between horses and can have severe consequences, it is very important to alert owners of horses which might be at risk of infection through contact with your horse or premises following an outbreak.