A surge of sheep measles in Hawke's Bay has sparked new warnings for farmers and dog owners.
As summer approaches, recorded cases of sheep measles are in some areas more than 50 per cent up on the same stage last year.
It has become particularly noticeable in areas close to Hastings, according to Ovis Management project manager Dan Lynch, of Palmerston North.
It was a problem that tended to increase with the proximity of sheep to the city limits, and the proximity of urban-raised dogs to sheep, he said.
Pet dogs were a common source of the problem.
Farmers are warned they should take every step possible to ensure dogs which have not been treated for sheep measles do not get on to their properties.
Sheep measles is the common name given to lesions in sheep meat caused by a tapeworm parasite, the primary stage being a tapeworm which infects dog intestines.
Eggs produced by the tapeworm in dogs are transferred to pasture where they are ingested by sheep.
There is no risk to human health but proliferation of the worms and cysts leads to downgrading of carcasses, or in the worst cases condemning of sheep, with consequent devastating impact on the bottom line.
Dogs should be dosed at least 48 hours before entering properties, Mr Lynch says.