A new case of bluetongue disease has appeared in the UK in the Greater London district of Watford.
According to the Department for the Environment, Food and Rural Affairs (DEFRA), a new 20km bluetongue protection zone has been set up which covers parts of west and north London extending into Buckinghamshire and Hertfordshire.
Another two new cases have also been found inside the existing bluetongue protection zone covering much of East Anglia and the South East and that zone has been extended further into Surrey and Cambridgeshire.
DEFRA says all of the animals are suspected to have been infected before the "vector-free period", declared in December when it was considered there was a low risk of the disease spreading because of the cold weather.
There are now 75 confirmed cases of the virus, which were detected during routine testing required before animals can be moved out of protection and surveillance zones.
Bluetongue disease is spread by midges and can be fatal to animals such as sheep and cows and was first confirmed in the UK in East Anglia on 28 September.
The surveillance zone remains in place over much of England and DEFRA says further cases can be expected.
Bluetongue is an insect-borne, viral disease which primarily affects sheep, occasionally goats and deer and, very rarely, cattle.
Evidence of bluetongue virus infection is present in cattle and farmed and feral deer in many areas of Australia but it has not been reported in the major sheep-growing areas; the disease does not affect humans.
The virus is also present in most countries of Africa, the Middle East, India, China, the United States, and Mexico.