All horses will be tested at Cambridge Stud following New Zealand’s first positive test result for Theileria equi, a protozoan that causes piroplasmosis.
Cambridge Stud CEO Henry Plumptre said the thoroughbred mare who returned the positive test earlier this month was imported under New Zealand protocols last year from France as a maiden and had been resident at Cambridge Stud since her arrival in February 2019. The mare was bought by a Cambridge owner at the Arqana sale in December 2018. She was negative for Theileria equi in a pre-sale test, was negative before going into quarantine for three weeks and was negative under New Zealand protocols, before departing Britain.
Part of the importation process requires that horses are treated for ticks. On arrival in New Zealand, the horse was in post-arrival quarantine and inspected by an equine veterinarian. An MPI vet checks arriving horses on arrival at the airport, at the quarantine location within 24 hours of arrival, around the middle of quarantine and then before release.
The mare was booked to be bred to an Australian stallion this year and was tested, along with nine other Cambridge mares, last week.
“We were informed of a possible positive and we immediately requested a second sample which is being tested this week. The implication is that she will be positive again,” Plumptre said.
Cambridge Stud was working with the MPI and its own vets at Cambridge Equine to test every mare at the stud.
“Fortunately the mare in question is known to have had direct contact with a very small number of horses, and given the main means of transmission by tick, the likelihood of further infection is considered very low. However, we have taken the cautionary route with the MPI and will test every horse on both properties at Cambridge and Karaka,” Plumptre said.
Horse exports on hold
Two shipments of horses to Australia were not able to go ahead as a result of the positive test.
New Zealand Equine Health Association Chairman Ivan Bridge said negotiations with Australia to resume trans-Tasman transport appear to be progressing positively.
“MPI Market Access is working on that right now and what that will most likely mean is we will be required to have two piroplasmosis tests carried out on a single blood test for all horses being exported to Australia in the short to medium term.”
Bridge said an immediate focus was to facilitate the transport of in-foal mares across the Tasman, who may travel only up to 300 days in foal.
“One of our priorities is ensuring those mares covered in the first five days of last breeding season are able to get to Australia by June 26.
“There is also a shipment of horses bound for Hong Kong via Sydney on June 7, so there is some haste,” Bridge said.
”Post Covid-19 air freight access is another complicating factor, almost the perfect storm”.
Bridge said he took “a lot of confidence” from the fact there have been no horses diagnosed with piroplasmosis symptoms on the property, or in the country, and the mare has been there since the beginning of 2019. ”So one would anticipate we are reasonably safe.”
“We are hopeful that the results from the samples of the cohort mares and other horse population on the property will come back negative, which will set a platform for us to move forward quite quickly and provide our trading partners some confidence.”
• Equine piroplasmosis is spread by ticks. Although New Zealand has ticks, they are not the species known to transmit the protozoa.
The disease is not directly infectious between horses, but in rare instances, it can also be transmitted between animals through contaminated medical equipment, such as needles or other invasive items.
Some countries that import horses from New Zealand, including Australia, require certification that New Zealand is free of Theileria equi. This positive test result means that MPI cannot currently provide that assurance.