The Ministry for Primary Industries (MPI) has completed testing all adult horses considered at risk of contracting Theileria equi infection through association with an infected imported thoroughbred mare at Cambridge Stud.
All 263 tests have returned negative results.
The horse concerned was imported to New Zealand for breeding purposes in February 2019 and was found to be infected with Theileria equi as part of standard export certification prior to onward shipment to Australia. The horse has not displayed any signs of illness in its time in New Zealand.
Ministry scientists worked with Cambridge Stud, whose professionalism and record keeping has been praised, to quarantine the horse and immediately test all adult horses that were either paddock mates of the infected horse or had grazed the same pasture as the animal. These 22 animals all tested negative for Theileria equi.
Subsequent testing was carried out on 241 other horses at the stud to provide confidence that the operation is free of the organism, and that there has been no transmission of it within the farm.
Theileria equi is an organism that can cause the blood condition Piroplasmosis which causes anaemia and poor condition. It is primarily spread from horse to horse by ticks. It is not infectious directly between horses, and the ticks that are known to transmit the disease are not a species present in New Zealand.
The situation temporarily halted the export of some horses from New Zealand to Australia as Australian importing requirements include certification from the New Zealand government that the entire country is free of Theileria equi.
Exports have already resumed under an interim arrangement and MPI continues to work with Australian authorities.
Negotiations are also underway with other importing countries and are also making good progress.
At the time of its import to New Zealand, the horse met all the necessary requirements including testing negative for Theileria equi within the required 21 days before its shipment. It had also undergone full quarantine in the UK before export and in New Zealand on arrival.