When blood escapes from the vessels into an open space, whether it be into one of the cavities of the body (chest or belly, etc.) or on to the surface, it is described as hemorrhage. If, instead, it passes into the tissues, as in the case of a black eye or a " corn", it is spoken of as extravasation. Bleeding may occur from an artery or a vein, or both at the same time. In the first case it is distinguished as arterial hemorrhage, in the second as venous, and in the third mixed.
For convenience of description different terms are employed to indicate the particular organs from which bleeding takes place. Thus bleeding from the nose is known as epistaxis ( to distil), from the lungs as haemoptysis ( blood, and to spit), from the stomach as hsematemesis ( blood, and to vomit), from the ear, ottorhgegia, etc. etc.
Hemorrhage may be the consequence of either disease or accident. In some animals it originates in a congenital weakness of the vessels, in which case their walls give way under very trifling causes, as when bleeding from the nose comes on in the course of a gallop, excitement, or effort in draught, or when hemorrhage from the lungs is provoked by coughing. Cases have come under the notice of the writer where, without any apparent cause, blood would ooze through the vessels of the skin and hang in drops from the hair at numerous points. This form of the disease is termed haemophilia ( , blood, and to love).
Hemorrhage as a result of disease is exemplified where the walls of the capillary vessels are weakened by fatty degeneration and fail to resist the pressure of the blood within them. The larger arteries sometimes become dilated and ulcerated, and break, from the same cause. Sloughing ulcers of the bowels, stomach, and other organs may lay open the blood-vessels and lead to serious or even fatal extravasation.
Fig. 203. - Fumigation of the Nostrils for Catarrh.
The accidental causes of hemorrhage are wounds and blows, the former resulting from cuts, stabs, and lacerations of the flesh.
Hemorrhage from the surface of the body is obvious, but internal bleeding is not always so. When it takes place into the lungs it may be evidenced by its escape from the nostrils; but when the escape is into the chest or belly, or other closed cavities, the outward indications of its occurrence must be sought for in certain manifestations of disordered function and physical signs. Of these the more suspicious are a pale or blanched appearance of the membranes lining the mouth, the nostrils, and the eyelids. The pupils of the eyes become dilated, and the eye itself presents a bright, glassy appearance. The breathing is deep and sighing, the extremities become cold, and patches of cold sweat appear on the body. The upper lip is raised from time to time, and if the head be elevated by placing the hand under the jaw, the animal staggers.
As the blood drains away, and supply to the brain fails, the muscles twitch and quiver and finally undergo general relaxation, when the body staggers and falls. Death from loss of blood is preceded by convulsions.
The course to be adopted in dealing with hemorrhage will depend upon the organ affected, and in external bleeding in some measure as to whether the flow is from an artery or a vein, or from smaller and less important vessels. If an artery be laid open through an external wound, the blood flows from it in jerks corresponding to the beating of the heart, and it is, besides, of a bright scarlet hue. If it proceeds from a vein, it passes from the wound in a continuous stream, and the colour is dark red or purple.
Where veins and arteries are divided at the same time these two colours are blended together, giving a colour intermediate between the two, or a light and dark streakiness, to the stream. If the vessel from which the blood escapes is of considerable size, and can be made accessible, the bleeding may be arrested by ligature, i.e. by tying it round tightly with a piece of clean carbolized silk or string. If it is an artery, the ligature should be applied to that side of the opening in the vessel nearest the heart, from which direction the blood is coming. If it be a vein, that side farthest from the heart will be selected. Pressure on the bleeding part, by means of the finger or a bandage, may suffice to stop the flow. Where the blood proceeds from a number of small vessels, a little cotton-wool applied to the broken surface will sometimes have the desired effect. Should it not do so, the part may be freely irrigated with cold water, or dressed with a solution of perchloride of iron, alum, or sulphate of copper. The application of the actual cautery (hot iron) may be made in some cases where the divided vessel is not large. The internal administration of turpentine, lead, opium, or tannic or gallic acid will increase the coagulating power of the blood and assist in filling up the breach.