Welsh Government said that infected animals, located in Powys and Monmouthshire, will be culled, with further surveillance and testing being undertaken on all holdings.
Investigations are ongoing to determine the source of the virus and the possibility of active disease circulation in Wales. Welsh Government will provide further updates once further information is available.
NFU Cymru Deputy President Abi Reader said: “The news that Bluetongue (BTV-3) has been confirmed on four premises in Wales this weekend is a concern to livestock keepers but not surprising given the number of cases reported across the border in recent weeks. We are aware that further surveillance and testing is now being undertaken to determine the potential source of infection.
"It is a reminder of the need for all of us as livestock keepers to remain vigilant for signs of the disease and if we have any suspicion of disease to report immediately to APHA on 0300 303 8268.
"NFU Cymru continues to recommend that farmers in Wales discuss the potential benefits of Bluetongue vaccination with their private vet to decide if it is right for them and if it represents the best way to protect their flock and/or herd."
Signs and symptoms
Bluetongue affects sheep, cattle and other ruminants. It is a viral disease spread by biting midges, which affects all ruminants (e.g. sheep, cattle, goats and deer) and camelids (such as llama and alpaca).
Symptoms vary across ruminants, but include fever, lesions, redness of the mouth, eyes, nose, reddening of the skin above the hoof, excessive salivation and nasal discharge. However, animals may show little or no clinical signs.
It does not affect humans or food safety – meat and milk from infected animals are also safe to eat and drink.
For more information on the signs and symptoms of bluetongue, visit: Welsh Government | Bluetongue