Bleeding from the lungs and bronchial passages is not of common occurrence in the horse, but sufficiently so to warrant a reference to it here.
The causes that bring it about are: (1) External violence, as when the chest is punctured by a stake or other sharp instrument; (2) undue fulness of the vessels of the lungs or bronchial passages, as in bronchitis, pneumonia, and obstructive heart disease; (3) ulceration of the tracheal or bronchial mucous membrane, as in glanders and tuberculosis, etc. Some cases come on during severe exertion and violent coughing without any other obvious reason.
Pulmonary, like nasal hemorrhage, is usually sudden in its onset, and may be slight or severe. The blood is mainly discharged from the nostrils, but some also flows from the mouth. Bleeding from the lungs, when profuse, is invariably attended with outbursts of convulsive coughing, during which the blood, whipped into foam, is projected through the nose and mouth. Moreover, the bronchial tubes may become more or less blocked when the breathing becomes quick and embarrassed; the horse shakes his head, paws the ground, and manifests signs of distress. In slight cases, such as occur in pneumonia and some specific fevers, it appears in small amount as a blood-stained discharge from the nostrils.
Here, as in bleeding from the nose, the patient must be placed in a cool, clean box and kept perfectly quiet. A little ice in the water will be of advantage in arresting the hemorrhage, but it is doubtful if the forcible administration of medicines is not rather mischievous than otherwise. A little ergotin injected beneath the skin, and free sponging of the face with cold water, is as much as can reasonably be done.
If in his water the patient can be induced to drink 4 ounces of sulphate of magnesia on two successive days, benefit will result from a free action of the bowels. The body should be well clothed so as to keep the surface circulation active.