Equine influenza

What is it ?
There are several strains of equine influenza virus, divided into 2 main groups:
-Type I was first isolated in 1956 in Prague
-Type II strain in Miami in 1963.
The last group are the most common. The highly infectious nature of the influenza virus, the rapidity with which it spreads, the seriousness of the illness, and the protracted period for which it prevents affected horses from racing or competing, all combined to bring about the requirement for all racehorses and most competition horses to be compulsorily vaccinated against the disease.

Geographical Spread
World-wide

Cause
Young, unvaccinated horses in crowded, poorly ventilated conditions especially at risk.

Symptoms
Infected horses have a dry cough. There is a nasal discharge that may start clear, but becomes thick and purulent. The horse has a temperature of around 103°F. Particularly dangerous are the secondary changes: these might include damage to the heart muscles, and lung damage that may trigger off COPD later: Foals are very susceptible to the disease and may die.

Treatment
Both complete rest (for at least 6 weeks in severe cases) as well as a good ventilation are essential. As a viral disease there is no specific treatment, other than using vaccination to prevent the disease. Bronchodilators reduce the effects of the infection on the lung and antibiotics are important to prevent secondary infections.