Safeguarding Flocks from EAE: Why Vigilance and Accreditation Matter

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Enzootic Abortion of Ewes (EAE) continues to be one of the most devastating infectious diseases affecting sheep flocks across the UK. Caused by the bacterium Chlamydophila abortus, EAE is the leading cause of infectious abortion in sheep—and its impact stretches far beyond animal health, threatening farm profitability and even human health, particularly for pregnant women.

The Hidden Threat

EAE is a silent invader. Infected ewes often show no outward signs of illness, making it easy for farmers to unknowingly introduce the disease when purchasing replacements. The damage only becomes visible at lambing time, when ewes abort two to three weeks early or deliver weak, non-viable lambs.

Once EAE takes hold in a flock, it becomes a persistent issue unless strict control measures, including vaccination, are implemented. Transmission typically occurs around lambing, through contact with aborted lambs, placentas, and contaminated environments. The bacteria can survive on pasture for several days and may also spread via clothing, boots, wildlife, birds—and even female goats.

The Economic Toll

The financial impact of EAE is staggering. Industry-wide losses are estimated at £15 million annually, with each ewe that aborts potentially reducing gross margin by £95. A 5% abortion rate can slash a flock’s potential gross margin by 10%, turning EAE into not just a health crisis, but a serious economic threat.

Prevention Through Accreditation

While vaccination is a key tool in the fight against EAE, it must be paired with robust biosecurity and sourcing policies. One of the most effective strategies is to purchase only EAE Accredited replacements—sheep that have been rigorously tested and proven free of the disease.

HISHA: Leading the Fight Against EAE

The Highlands and Islands Sheep Health Association (HISHA) plays a vital role in this effort. Established in 1988, HISHA is a farmer-led organisation committed to maintaining the high health status of breeding and hill sheep flocks in the Highlands and Islands of Scotland.

HISHA’s mission is clear: keep EAE out of the region and supply hardy, healthy, EAE Accredited breeding sheep to producers across the UK.

HISHA flocks are monitored by SRUC Veterinary Services and must meet stringent criteria to achieve EAE Accredited status, including:

• A minimum of two years of disease-free testing
• No use of EAE vaccines
• Mandatory investigation of any abortions

This rigorous approach ensures HISHA-accredited sheep are among the safest replacements available, offering peace of mind to farmers and helping protect the wider industry from the devastating effects of EAE.

A Call to Action

Farmers are urged to remain vigilant and proactive. By implementing strong biosecurity measures, using vaccination where appropriate, and sourcing replacements only from trusted, accredited suppliers like HISHA, the industry can reduce the prevalence of EAE and safeguard both animal welfare and farm profitability.

For more information on HISHA and how to source EAE Accredited sheep, visit www.psghs.co.uk and contact Orkney, Dingwall, United Auctions, or Aberdeen and Northern Marts for HISHA EAE sales.

Posted by SRUC Veterinary Services on 19/09/2025