Authorities have confirmed the presence of highly pathogenic avian influenza in poultry at a large site in Pembrokeshire, the second case of the virus in Wales this week.
A 3km Protection Zone and 10km Surveillance Zone have been declared around the infected premises to limit the risk of disease spread.
Within these zones, bird movements and gatherings are restricted and all holdings that keep birds must be declared. The measures are stricter in the 3km Protection Zone.
The Welsh government said it was 'vital' for farmers and other bird keepers to 'remain vigilant' and ensure the 'very highest levels of biosecurity in place'.
It comes after a case of avian influenza was confirmed earlier this week at a premises in Gwynedd, the first case of bird flu in Wales in six months.
The latest case is Wales' seventh outbreak of bird flu since the start of this year's avian influenza crisis, which began in late October 2021.
Deputy Chief Veterinary Officer for Wales, Dr Gavin Watkins said this week's outbreaks were a 'cause for concern'.
“Keepers of birds must be vigilant and ensure they have the very highest levels of biosecurity in place. There is always more that can be done to protect your birds.
“As we move into the autumn and winter, I urge you all to review the measures you have in place and identify areas of improvement," he said.
"Think about risks from direct contact with wild birds, especially waterfowl, and also the things that could be contaminated by bird droppings – clothing and footwear, equipment, vehicles, feed and bedding.
"Make improvements where you can to prevent further spread of this devastating bird disease. Good biosecurity is always key in protecting animals from disease.”
Last week, the UK’s Deputy Chief Veterinary Officer declared a regional Avian Influenza Prevention Zone (AIPZ) across the South West of England to mitigate the risk of further outbreaks of disease occurring.
It is now a legal requirement for all bird keepers in the counties of Cornwall, Devon and parts of Somerset to follow strict biosecurity measures.
Recently, the region has seen an increase in the number of highly-pathogenic avian influenza cases in both poultry and in captive birds.
The latest case was confirmed on 8 September in commercial poultry at a farm near Torpoint, in Cornwall.
