Continued warm, moist weather has vets worried stock will get facial eczema, Wanganui Veterinary Services owner Tom Dinwiddie says.
He is especially concerned for lifestyle block owners, who may be less aware of the disease and have fewer options for moving animals.
Facial eczema is caused by grazing animals eating the spores of a particular fungus as they graze grass. The spores produce a toxin that can eventually lead to liver damage and death.
Red, swollen skin and an avoidance of direct sun are early signs of it. The animals will also be restless, and shake or rub their heads and bodies. This can eventually rub their skin off, making them vulnerable to fly strike.
Wanganui Veterinary Services has been monitoring the number of those damaging fungus spores since early February.