With enzootic abortion of ewes (EAE) responsible for more than a third of abortion cases in sheep every year, a new campaign has been launched to encourage farmers to vaccinate in advance of tupping so unnecessary lamb losses and inappropriate use of antibiotics can be prevented.
Dr Fiona Lovatt, independent sheep veterinary consultant, who leads the cross-industry Sheep Antibiotic Guardian Group, says farmers often do not realise EAE is responsible for more than 35 per cent of all abortion diagnoses, the largest cause by far.
Despite this, only one million of the 3.5m replacement ewes in the national flock each year are vaccinated against EAE.
She says: “Any sheep farmer who either buys in ewes for replacements, or has close neighbours who also lamb sheep, risks bringing enzootic abortion into their flock.
“Once the disease infects an unvaccinated flock, some ewes are ‘programmed’ to abort at their next lambing, leaving no choice but to put remedial measures in place – usually including both vaccination and antibiotic treatment.”
This means EAE is a disease which once in a flock, carries high costs, both financially and emotionally in terms of lamb losses and farmer stress.
“Hence it is important flocks receive appropriate vaccination at least four weeks before ewes go to the ram and avoid the inappropriate use of antibiotics closer to lambing,” says Dr Lovatt.
“There are areas of the country where sheep farmers have routinely used whole flock blanket antibiotic treatment close to lambing to prevent abortion. There is absolutely no need for this; it is neither appropriate for disease control, nor cost-effective.
“Misuse of antibiotics contributes to the development of antimicrobial resistance and ultimately this will be detrimental to flock health as it becomes harder to treat common diseases.”
Dr Lovatt points out a single dose of EAE vaccine costs about £2.40 and is an investment that effectively lasts the ewe for its lifetime in the flock, protecting against losses.
In contrast, abortion or stillbirth – which accounts for about a quarter of all lamb losses each year – costs more than £25 for every single lost lamb.
“Every injection of antibiotics also costs an additional £1,” says Dr Lovatt. “But it is just a ‘sticking plaster’ with short-lasting effectiveness in terms of disease control but long-lasting damage in terms of mounting resistance.”
However, she adds time is of the essence, and recognising the issue now means sheep farmers still have time to plan, prevent disease spread and protect their flock by getting them vaccinated before the critical cut-off point four weeks before tupping.