Horses Test Clear for Exotic Equine Disease

9 August 1999

All the horses tested for the exotic horse disease equine infectious anaemia (EIA) in New Zealand have been cleared.

EIA is an infectious disease of horses, with no known treatment, caused by a virus spread by biting flies and dirty needles. The disease is not present in New Zealand's horse population.

A brood mare imported from New South Wales, Australia to New Zealand in early June tested positive to the disease was destroyed.

Trace-back established that eleven horses had had direct or indirect contact with the imported mare. The in-contact horses were on four separate properties due to movement of horses that came over in the original consignment.

Movement restrictions were imposed on all four properties, and the in-contact horses were isolated and received daily treatment with insecticide sprays to reduce the risk of transmission. Insect trapping early in the isolation period indicated stable fly, the only likely vector present in New Zealand, was present, but in very low numbers.

All isolated horses were tested at the start of the isolation period, after 30 days, and after 60 days, with all negative results. Although isolation was originally intended to run for 45 days, this period was extended to 60 days on the advice of experts in order to provide an appropriately conservative level of confidence.

The negative results mean all restrictions on in-contact horses and their premises have been removed. Stamping out has been completed, and New Zealand is once again considered free from EIA.


The infected brood mare was one of a six imported from New South Wales on 24 May 1999. The last case of EIA in New South Wales was in 1986. Queensland is the only part of Australia known to have had EIA in recent times.

MAF requires pre-export testing of horses for EIA prior to all imports. The Australian Quarantine Inspection Service (AQIS) conducted the testing, and certified that the brood mare in question was negative.

Tests results for another horse in the same consignment were pending and not available at the time of export. MAF allowed that horse to be imported, but quarantined it on arrival in New Zealand, pending results from Australia. AQIS reported to MAF that one positive and one negative result had been obtained from this horse. MAF tested the horse and found it to be negative for EIA. Following this result the horse was released from the quarantine on 3 June.

In the evening of 3 June 1999, AQIS reported to MAF that a labelling mix up in the Australian laboratory had occurred, and that another horse travelling in the same consignment as the quarantined horse was suspected to be EIA positive. As soon as this information was received, MAF traced the horse - the infected brood mare - and issued a Restricted Place notice on the property where it was grazing in an isolation paddock on 4 June 1999.

Media inquiries to:

Dr Barry O'Neil, Director of Animal Biosecurity, Ministry of Agriculture and Forestry (04) 474 4100
Matthew Stone, National Adviser, International Trade, Ministry of Agriculture and Forestry (04) 474 4100
Debbie Gee, Director, Corporate Communications, Ministry of Agriculture and Forestry (04) 474 4258



Last Updated: 20 September 2010

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