The discovery of a strain of avian influenza in a sheep for the first time should be a reminder to sheep keepers of the importance of biosecurity on holdings with poultry, says the National Sheep Association (NSA).

A single sheep in Yorkshire was discovered positive of highly pathogenic H5N1 avian influenza over the weekend.

The sheep was tested after H5N1 has been found in poultry on the farm. Blood and milk samples were positive.

Importantly, NSA stresses that the case is confined to one small holding and is not a food security risk.

NSA Chief Executive Phil Stocker says: “This is not a threat to food safety of consumers and it’s very important to make that clear.

“What this shows though is the importance of biosecurity and an understanding of what biosecurity means. In the sheep industry we often think the term just refers to buying in stock, but in this instance sheep and poultry have mixed on the same farm, resulting in the transmission of avian influenza.”

Mr Stocker adds that mixing of species is questionable at the best of times, but should be avoided when England is undergoing a period of mandatory housing measures for poultry due to bird flu outbreaks.

Defra has placed England in an avian influenza protection zone with mandatory biosecurity measures. Furthermore, there are 13 regions in which mandatory housing measure apply: Cheshire, Hull, East Riding of Yorkshire, Herefordshire, Lancashire, Merseyside, Norfolk, North Yorkshire, Shropshire, Suffolk, Worcestershire, and York.

Helen Roberts, NSA Cymru Development Officer, says: “Although this news is not welcome at this time of year, it does give us the opportunity to remind ourselves of the importance of good biosecurity especially with lambing for many just around the corner and to be vigilant with our flock. We want to do our utmost to retain our high health and welfare standards of the national flock.”

A Defra spokesperson says: “While this is the first time avian influenza virus has been detected in a sheep, it is not the first time influenza of avian origin has been detected in livestock in other countries. There is no evidence to suggest an increased risk to the nation’s livestock population.”

Read the latest Defra update at Bird flu (avian influenza): latest situation in England - GOV.UK