Respiratory

Chronic inflammatory airway disease caused by dust/mould allergens, with bronchospasm and increased mucus.

An acute cough is a symptom of suddenly arising airway irritation, often as part of a viral or bacterial infection of the upper and lower airways. It can be harmless and brief, but with fever, breathing difficulty or impaired general condition it may indicate a more serious infection and is often contagious in the stable.

In EIPH, bleeding from small lung vessels into the airways occurs under high exertion, triggered by very high pressures in the pulmonary capillaries during intense work. It mainly affects racehorses and high-performance horses and often goes unnoticed, as only some horses show visible nosebleeds.

In sinusitis, one or more of the air-filled paranasal sinuses become inflamed, often with an accumulation of secretion or pus. It arises primarily after airway infections or secondarily through diseased cheek-tooth roots whose tips reach into the maxillary sinus.

In roaring, the nerve supply to the laryngeal muscles — usually on the left side — is impaired, so that a vocal-fold cartilage does not open sufficiently on inhalation. This narrows the airways under exertion and produces the typical whistling breathing sound; large horses are especially affected.

In DDSP, the rear edge of the soft palate displaces over the epiglottis and temporarily obstructs the airways, especially at fast work. Typical is a gurgling breathing sound on exhalation with a sudden drop in performance; many horses start normally and only break down at high speed.

Pleuropneumonia is a severe bacterial infection of the lung and pleura, in which inflammation and fluid/pus accumulate in the chest cavity. It often occurs after long transports with a fixed, raised head (shipping fever) and is a potentially life-threatening disease that must be treated quickly by a vet.