Sprain of the back.—Sprain of the back, particularly in the region of the loins, is not an uncommon accident among cattle. It is liable to occur from the animals slipping with both hind feet side wise so as to twist the back, or from slipping violently backward so that great stress is thrown on the loins. The patient moves with difficulty, using the hind parts in a guarded manner, as if afraid of causing severe pain. Occasionally, if the sprain is severe, the animal will rise with difficulty. Pressure on the back in the immediate region of the loins causes pain. Such cases may be mistaken for paralysis, and, in fact, in severe cases, during the early stages of the injury, although the nerve supply is not interfered with, the injury to the muscles and resulting pain is so great that the condition is almost equal to paralysis, although liable to be attended with more favorable results. Hot applications, such as blankets wrung out of hot water and changed often, will be likely to afford relief during the earlier stages. Afterwards the blister mentioned for sprain of the shoulder may be applied with advantage.
FRACTURES (BROKEN BONES).
Bones may be accidentally broken in many ways and from different causes. Fractures in general are liable to be produced by external force suddenly and violently applied, either directly to the part or at a distance, the force being transmitted through the stronger bones until it expends itself by breaking a weaker one remote from the seat of the injury. Occasionally violent contraction of muscles is sufficient to break a bone. Certain bones, those of the limbs in particular, owing to their exposed position, are more liable to fracture than others. Owing to certain predisposing causes, such as age, habit, or hereditary constitutional weakness, the bones of some animals are more easily fractured than those of others. The bones of an animal advanced in years are more subject to fracture because of the preponderance of inorganic matter rendering them more brittle. They are also occasionally rendered liable to fracture by a previously existing diseased condition. Fractures are divided into four classes—partial, simple, compound, and comminuted.
Partial fractures.—Partial fractures are those which are liable to occur in a young animal in which the preponderance of animal matter or the semicartilaginous condition of the bone renders it tough, so that even when considerable force is applied the bone bends, breaking on the side opposite that to which the force was applied, after the manner in which a green stick bends and breaks.
Simple fractures. Simple fracture is one in which the bone is severed in two parts, transversely, longitudinally, or obliquely, without serious injury to the adjoining structures.
Compound fractures.—Compound fracture is one in which there is an open wound permitting the air to communicate with the ends of the broken bones.
Comminuted fractures.—Comminuted fracture is one in which the bone is shattered or divided into a number of fragments.
Complicated fractures.—Complicated fracture is one in which other structures surrounding the bones are injured.
General symptoms of fracture.—When a fracture of one or more of the large bones of a limb occurs, symptoms are sure to be well marked. After the accident the animal refuses to touch the foot to the ground and, if compelled to move, does so with great pain and reluctance. There is more or less shortening of the limb, with trembling of the muscles in the vicinity of the injury; deformity, and increased mobility, so that, instead of the natural joints of the limb and the natural, muscular control of their motion, a new joint, over which the animal has no control, is formed where the fracture occurred. As the leg, shortened by the ends of the bones being forced past one another from the muscular contraction which invariably takes place, hangs dependent from the body it swings in an awkward and unnatural manner, permitting the toe and foot to assume positions in their relations to other parts of the body which otherwise would be impossible. If the fractured bone is so situated that the parts may be moved one upon another, a grating sound, known as crepitus, will be heard.