Page 698 - The Veterinary Care of the Horse

airway inflammatory disease (SAID).

VetBooks.ir Causes

It is caused by exposure to irritants and allergens found in the stable environment. These
include small airborne particles such as inorganic dust, fungi, endotoxin, mite debris and

noxious gases. Dusty hay and bedding together with poor ventilation can trigger the
condition, which results in inflammatory changes occurring within the airways leading to

increased mucus production.

Bacterial, mycoplasma and viral respiratory infections may be a trigger for the development
of IAD. Horses with exercise-induced pulmonary haemorrhage (EIPH) from high intensity

work at speed may be more susceptible to IAD.

Clinical signs

These include:

• Nasal discharge, which may be clear, white or coloured

• Poor performance – this may be the only sign in mild cases
• Delayed recovery from exercise

• Coughing at exercise

Affected horses usually have a normal temperature and do not show the increased respiratory
effort associated with recurrent airway obstruction (RAO).

Diagnosis

The diagnosis is made on the clinical signs and confirmed by endoscopic examination of the
respiratory tract to:

• Assess the amount of mucus in the airways

• Collect samples of the respiratory secretions for cytology and bacteriology using
bronchoalveolar lavage (BAL – see page 425)

Treatment

This consists of management changes with medication if necessary.