Equine influenza

Equine influenza virus

Legal Status: Notifiable Organism

Status in New Zealand: Not in New Zealand

Organism: Micro-organism

Pest and disease search

This disease is NOT in New Zealand

Report any suspected cases to hotline, ph 0800 809 966

General Information
Factsheets
Media
Useful Resources

General information

Equine Influenza (EI) is a major viral respiratory disease. It can cause significant disease in adult horses and can be fatal for foals.

The disease lasts several days with full recovery taking two to three weeks, although some horses may develop complications.

The disease occurs widely throughout the world and Australia and New Zealand were the only two countries with significant horse populations that had been free of it. The recent reported outbreak in Australia is of great concern to both our industries.

EI is a highly contagious disease that is transmitted through direct contact with horses and from contaminated items (people, vehicles and equipment). It has a 100 per cent infection rate among horses who have not previously encountered the virus. EI is similar to other viral conditions which cause coughing and some discharge from a horse’s nose. However, the influenza is more severe – horses develop a temperature and a dry, hacking cough.

Horses with EI become tired and do not eat, often for days. The disease remains infectious for up to 7-10 days.

The virus is present in the aerosol created by coughing horses and spread over 32 metres has been recorded. Longer-distance aerosol or windblown transmission is a possibility.

The disease has a very short incubation period (time from infection to symptoms) of 1-5 days.

The disease starts with a high fever (often 40-41 degrees C). Animals are often depressed, off their food, are stiff and reluctant to move. The predominant clinical sign is a dry unproductive, explosive cough. Nasal discharge may be absent or clear in the early part of the disease, thickening later.