Successful outcome of Theilera equi response

New Zealand Equine Health Association
World Organisation for Animal Health

A declaration of New Zealand’s freedom from the equine blood disease Theilera equi was recently posted on the World Organisation for Animal Health’s (OIE) website.

In April 2020, a four-year-old thoroughbred mare destined for stud in Australia tested positive for T. equi in routine pre-departure testing. Gene sequencing testing then confirmed the horse was infected with T. equi, although she was clinically healthy. The mare had been imported from France in February 2019 for breeding purposes. Investigations concluded that she had been infected before import to New Zealand. Because the mare had been resident in New Zealand outside of quarantine, our country lost its disease free status for T. equi, causing significant concern to the equine community who faced the possibility of a new endemic disease that could severely impact the health of the New Zealand horse population. In addition, there were extra immediate costs to horse exporters who now had to comply with the additional testing requirements associated with exporting from an infected country.

A response team of representatives from MPI and the equine industry, represented by members of the Equine Health Association (NZEHA), was set up. The best scientific and veterinary resources were assembled to assess the transmission risk and design a testing regimen to determine the extent of any spread of the disease in New Zealand. After extensive research and testing no evidence was found that the disease had spread - via ticks or other mechanisms - beyond the single imported horse.

The joint effort by MPI and NZEHA has resulted in most export markets remaining accessible to New Zealand horse exports, and NZEHA spokesperson Trish Pearce says it’s hoped that the OIE declaration of freedom will see the quick removal of the extra testing requirements that most countries added last year, thus relieving the equine exporters of the extra costs and inconvenience they have faced over the past nine months. The full declaration can be read HERE.