Farmers in the South and West are being warnednot to be prescriptive when it comes to selecting the correct wormer this summer. Many farms are experiencing mixed worm infestations with early fluke infection also a concern in some areas.

Data from Parasite Watch, the real-time parasite monitoring service from Zoetis, has foundpositive fluke samples detected by Copro-Antigen tests in addition to high roundworm counts via Faecal Egg Count (FEC) tests.

The mixed burdens make it vitally important farmers know which worms are present and causing production losses on their farms so they can use the appropriate product, said Zoetis vet Dr Dave Armstrong.

He said: “It is quite early to be seeing fluke detected by Copro-Antigen tests as they can only be detected from six to eight weeks of age. These test results mean the early immature fluke would have started infecting ewes and lambs back in May, which is a lot earlier than usual.”

“With us seeing some high counts in the South West, this may just be the tip of the iceberg, as although there are not many cases reported, there may be a high level of infection.”

He added: “The mild winter and warm spring combined with the wet weather has provided perfect conditions for fluke and their host the mud snail. This is why we are seeing these early cases.”

Two farms in Carmarthenshire have seen high fluke counts with cases also being reported in Worcestershire and Devon.