Sheep farmers are being encouraged to investigate all unexplained abortions or stillbirths in flocks when it has been claimed not enough farmers report and investigate unexplained reproductive losses among livestock.

According to Ruminant Health & Welfare (RH&W) chairman, Nigel Miller, veterinary surveillance is vitally important to identify disease threats on farm, and to monitor and map the health status for the country’s national herd and flock.

“Abortion investigations are a powerful tool which enable the early detection and management of new or re-emerging conditions on farm; at national level abortion investigation data identifies risks and maps their impact.

“This valuable information provides veterinarians and livestock managers with flock or herd risk management priorities and help to identify where steps can be taken," said Mr Miller.

He added that many farmers may be deterred from investigating reproductive losses due to the distance of their farm from laboratory facilities, however easy-to-use abortion sampling kits are available and make submitting the right samples relatively easy. Especially when transporting the foetus and placenta to the investigation centre is not practical.

“Both farm vets and veterinary laboratories provide guidance on the submission and sampling of aborted material with both the Animal and Plant Health Agency (APHA) and SRUC providing user-friendly kits for sampling, to make the submission of quality material easier,” adds Mr Miller.

As a rule of thumb, all farmers experiencing abortion levels above 2% in their herd or flock, or three or more cases, should seek a full veterinary investigation. This involves the investigation of the aborted material and placenta, supported by blood testing affected animals when required.

He says high quality samples are crucial and can underpin good diagnostic rates in sheep.

No firm diagnosis is not the end of the story. The systematic abortion investigation approaches used in laboratories is about ruling out conditions as well as attempting to bolt down a firm diagnosis. When no firm diagnosis is achieved a list of conditions which have been ruled out can often be provided – the negative list. Farm vets can help clients to gain value from investigation reports and where appropriate highlight features of the negative list which are significant. The negative list can often rule out conditions which are of real concern to the flock or herd manager.

Farmers who experience an abortion or stillbirth in their cattle or sheep are advised to speak to their vet and contact APHA or SRUC about getting an investigation carried out.

FlockCheck 2023

Sheep farmers in England, Scotland and Wales, can also ask their vet to blood test their flock for exposure to toxoplasmosis and enzootic abortion (EAE), following the launch of MSD Animal Health’s 2023 FlockCheck diagnostic scheme.

Ewe reproductive failure, neonatal lamb disease and mortality are the three biggest factors limiting better flock productivity – with toxoplasmosis and enzootic abortion continuing to be significant causes of these unwanted flock heath issues.

As in previous years, sheep farmers that experience more than 2% of their flock barren or aborting this lambing season are being encouraged to contact their vet to take advantage of the subsidised diagnostic scheme.

“Farmers can continue to take advantage of this subsidised scheme by asking their vet to take blood samples from six to eight aborted, unvaccinated ewes, or from barren ewes or ones that have produced weakly lambs,” explained MSD Animal Health veterinary adviser Dr Kat Baxter-Smith.

She added that the blood test has proved to be an extremely useful flock diagnostic tool in terms of helping to identify the potential presence of any key underlying productivity limiting disease.

“Experience has shown that the results certainly help vets and their farmer clients make more informed decisions about appropriate flock health measures.”

Annual FlockCheck blood test results consistently demonstrate that a significant proportion of aborted ewes tested have been exposed to either toxoplasmosis or EAE – and sometimes both.

For example, 2022 results showed nearly 75% of 374 sheep farms had been exposed to toxoplasmosis and 18% to EAE2. This is consistent with a recent AHPA analysis showing that between 2002 and 2019, toxoplasmosis and EAE have been the most common diagnoses of sheep abortion.

According to Dr Kat Baxter-Smith, both these infectious disease causes of abortion can be responsible for reducing the number of lambs per ewes mated, which can increase workload and stress during lambing.

Profit may also be reduced significantly, she stressed, but using FlockCheck which can help improve a flock’s potential and overall economic performance.

“For example, toxoplasmosis, caused by infection with the Toxoplasma gondii parasite, does not just cause abortion. It is also the main infectious cause of early embryo loss in sheep and a very common cause of barren ewes or weak, sickly live lambs. It is likely that almost all flocks in Great Britain have been in contact with this endemic parasite, which means all breeding sheep should be considered at risk.”

Dr Baxter Smith also explained that one of the main reasons for such high levels of toxoplasmosis is that sheep can become infected very easily.

Sheep pick up the toxoplasma parasite from the environment and so normal biosecurity measures are not enough to control the disease.

Infected cats shed toxoplasma eggs in their faeces and sheep become infected when they ingest these eggs from contaminated pasture, feed and water. The eggs are tough and can survive in the environment for more than a year, which means farmers need to take steps to protect their sheep.

“Fortunately, the disease can be controlled effectively by a simple vaccination regime. What’s more, the costs of a vaccination programme can be easily covered by a reduction in future flock barren and abortion rates. In reality, every ewe should ideally be vaccinated before she breeds because of the widespread disease threat and the significant financial losses,” she said.

The subsidised FlockCheck diagnostic service allows vets to identify whether toxoplasmosis or EAE (or both) are likely to have been involved in any aborted lamb losses, barren ewes or numbers of weak, sickly lambs. This aids the decision for (and identifies the potential value of) pre-tupping vaccination programmes.

Sheep farmers interested in taking advantage of this industry support from MSD Animal Health to help reduce the risk of lower productivity, should contact their local practice as soon as possible.

This year’s FlockCheck scheme commenced on February 1, 2023 and runs until June, 30, 2023.