FARMERS are being urged to beware after an outbreak of a rare and fatal cattle disease in Dorset.

There have been three confirmed cases of Malignant Catarrhal Fever (MCF) in three cows on three different farms in East Devon and West Dorset.

The disease is spread to cows from sheep, which are usually not harmed.

The outbreak has been confirmed by Dorset-based Synergy Farm Health and farmers are being urged to be especially vigilant where cattle and sheep are grazing in succession.

Vet Alasdair Moffett said: “The only known risk factor for MCF is being around sheep and in each of the three cases the common link was cattle grazing in a field that had previously grazed sheep. Risks can also increase around lambing time. This disease is caused by a sheep herpes virus and is usually fatal for the unfortunate cow but does not cause any disease in sheep. I have only seen two other cases of this condition in the last eight years so it is a surprise to find three cases in one month so close together.”

The three cows presented with very high temperatures, lack of appetite, painful red eyes which develop a blueish colour across the cornea.

The cattle also find light extremely painful and cannot tolerate daylight. Cows and sheep do not have to be in the field at the same time as the incubation period can be long and clinical signs in a cow can take up to a month to appear.

Dairy farms renting out fields for sheep grazing during the winter or mixed farms would be most at risk of the disease.

The team of 28 farm focused vets at Synergy monitor unusual or unexplained conditions between themselves via WhatsApp, providing quick diagnosis and surveillance.

Alasdair added: “We can blood test live animals to confirm this disease as some of the symptoms could also look like BVD, severe IBR or listeria. Once confirmed, we would put the animal down on welfare grounds as there is little likelihood of survival.”