A Taranaki sharemilker says an outbreak of facial eczema is hitting cows hard and fast.
The farm Antony Neill works on has just lost four cows to the disease, while over half of the herd have been infected.
He says the warm, damp weather provides the perfect conditions for the disease cultivate.
Mr Neill believes it's the worst outbreak of facial eczema he has ever seen.
Taranaki's Federated Farmers president, Harvey Leach, says the weather is fuelling the problem - which starts with short pastures causing cows to graze closer to the ground where the facial eczema spores are.
He says it's hard to tell the extent of the outbreak, but confirms it's an issue for farmers around the country.