Page 641 - The Veterinary Care of the Horse

• history of recent contact with a confirmed case of the disease.

VetBooks.ir How does the virus cause the illness?

The disease is spread by inhalation of virus released into the atmosphere as an aerosol by
coughing and blowing. Once inhaled, the virus invades the lining epithelium of the trachea,

bronchi, bronchioles and alveoli. The airway lining becomes swollen and inflamed, resulting
in tracheobronchitis. Patches of the epithelium slough off and these changes disrupt the

clearance of mucus and other debris from the airways.

Complications

• Adult horses sometimes develop a secondary bacterial infection.

• Young foals are at risk of developing pneumonia which can be fatal.

• Occasionally, the virus spreads from the respiratory tract and can cause damage to the
liver or the muscle of the heart.

Treatment and management

There is no specific treatment for respiratory viruses in the horse. Non-steroidal anti-

inflammatory drugs can give symptomatic relief and help bring the temperature down. If the
horse develops a secondary bacterial infection, antibiotics are given. All horses with
respiratory infections should be given complete rest. Ideally, they should not recommence

any strenuous exercise until two weeks after apparent recovery. Following recovery from
equine influenza, horses are more susceptible to respiratory infections for a period of 3–4

months. Over-exercise and stress should be avoided.

STABLE MANAGEMENT

Good stable ventilation and management are essential. Exposure to dust and spores should be

minimized as horses with respiratory infections are susceptible to developing recurrent
airway obstruction (RAO). If hay is fed, it should be of good quality and soaked. If weather

conditions permit, affected horses benefit from being turned out into a small paddock for at
least part of the day once their temperatures have returned to normal. This is especially

important in the recovery stages.

Control

Since the disease is spread by inhalation of virus released into the atmosphere as an aerosol