The Sheep Veterinary Society (SVS) and Sheep Antibiotic Guardian Group (SAGG) are disappointed by the lack of enzootic abortion (EAE) vaccine this tupping season. The organisations are also aware that this will have a significant impact on sheep farmers and the flocks that currently rely on effective vaccination to control disease. They have, therefore released new advice for when an enzootic abortion vaccine is unavailable.
This press release aims to offer a measured response to support vets and farmers who will need to make difficult decisions for their flocks.
Much of the group’s previous advice for when the EAE vaccine is unavailable has not changed:
- When faced with an aborting ewe, it is important that the ewe is isolated from the rest of the flock and that samples are taken to diagnose which abortion agent is responsible
- It is not appropriate to use routine prophylactic antibiotics to control abortion – use of antibiotics in late pregnancy is only acceptable to protect other ewes in the group in face of an outbreak or in a group of ewes following a confirmed laboratory EAE diagnosis in the immediately preceding year
Further advice for when the EAE vaccine is unavailable
For flocks that have previously been regularly vaccinated against EAE, there will be a small cohort of unvaccinated replacement ewes this year. However, the risk to them is low if the remainder of the flock is protected. They should be marked and vaccinated next year when they are not pregnant.
For flocks that are at high risk of disease (perhaps due to current or recent EAE abortion outbreak or following the introduction of EAE-shedding ewes into an unvaccinated flock) then there are a couple of options:
- There is an inactivated vaccine (Inmeva; Hipra) that may be appropriate to use. Note that two doses are necessary with the first dose given at least five weeks before mating, the second dose given three weeks after the first, and a further booster required within a year. This vaccine can be safely given during pregnancy with efficacy demonstrated in the mid trimester, but its use is not recommended in the final month of pregnancy
- Unvaccinated ewes at high risk of disease (confirmed by laboratory diagnosis) may be given a single injection of oxytetracycline (at 20mg/kg) between day 91 and day 126 of pregnancy. For groups with lambing spread over a four to five weeks period, they should be injected exactly three weeks before the first ewe is due to lamb
It is not appropriate for any flock to be given a routine prophylactic antibiotic without a confirmed laboratory diagnosis of EAE in the current or previous lambing season. Even in this circumstance, it is appropriate for the vet to undertake separate risk assessments for different cohorts of ewes.
Further information about the Inmeva vaccine is available from representatives of Hipra UK and Ireland Ltd.
Vets can contact their MSD Animal Health to access an information sheet with advice for the control of EAE in the situation of limited or unavailable EAE vaccine.
