The most recent maps produced for the Northern Ireland (NI) and Republic of Ireland (ROI) bovine viral diarrhoea (BVD) programmes show significant progress in reducing the incidence of the infection.

The maps were compiled by the Centre for Veterinary Epidemiology and Risk Analysis (CVERA), University College Dublin (UCD).

They show that progress has been made in 2023 thanks to the efforts of farmers and industry partners.

BVD maps

The anonymised maps have been produced through an ongoing collaboration between Animal Health Ireland (AHI) and Animal Health and Welfare NI (AHWNI) who coordinate the respective programmes, and the Department of Agriculture, Environment and Rural Affairs (DAERA) and the Department of Agriculture, Food and the Marine (DAFM).

The maps display a higher level of infection in NI compared to the ROI, with the need for the highest levels of biosecurity in infected herds, particularly in Co. Armagh, according to AHWNI.

In NI, the animal level incidence has fallen from 0.264% at the end of 2022 to 0.211% at the
end of 2023.

The herd level incidence has decreased by over 76% since the start of the compulsory programme.

The further drop in disease levels in NI in 2023 has occurred due to several factors, in particular, there has been a notable decrease in the number of Persistently Infected (PI) animals that have been retained for 28 days following disclosure of positive results.

As a result, the risk of viral transmission to livestock on those farms and to neighbouring farms has been reduced, according to the agencies.


The NI BVD Implementation Group continues to request new legislation that will address the risks presented by movement of transiently infected or ‘Trojan’ animals out of breakdown herds.

The legislation would also provide for the sharing of information to allow other herds to make informed decisions about herd biosecurity and purchases.

AHWNI has said that it continues to engage with all herd owners whose herds are in breakdown situations, to advise on how the virus can be eradicated at the farm level.

AHWNI chief executive, Dr. Sam Strain commented: “The maps demonstrate the substantial advances that have been made in tackling BVD through both programmes.

“Crucially, the number of Persistently Infected animals that have been retained within NI has reduced very substantially, reflecting the considerable efforts of farmers and industry partners in addressing the infection.

“However, the contrast with ROI illustrates both what can be achieved with a wider range of programme tools, as well as what still needs to be done in NI.”