Page:The American Cyclopædia (1879) Volume XVI.djvu/353

 VETERINAKY SCIENCE 333 until the abscess bursts. The rupture of the abscess is the signal for improvement, the sac gradually contracts and heals out, the general health is restored, and the animal thrives bet- ter than before the illness. In treatment the aim must be to support the strength, and favor the formation of matter between the jaws. Feed liberally on boiled oats or barley or warm bran mashes, to be eaten from a nose bag, and poultice or assiduously foment the swelling until nearly ready to burst, when it may be opened with a lancet, and the fomentations con- tinued at intervals. Medicine is rarely wanted. When the matter forms in unwonted situations the treatment will not differ, and the danger to life will depend on the importance of the parts involved. (See also BOTS, and GLAN- DEKS.) III. DISEASES OF BONES. Some of the most important maladies of the horse originate in inflammation of bony tissue. As types the familiar bone spavins, splints, and ringbones may be referred to. All are alike due to some injury of the bone or of its fibre-vascular cov- ering, causing exudation of lymph from the vessels and the hardening of this lymph by the deposition of earthy salts. All bone is perme- ated by minute blood vessels, around which and between the concentric bony plates are rows of microscopic particles of soft animal matter (nuclei), which preside over the nutri- tion of the part. The vessels are mainly de- rived from the fibrous membrane investing the bone. When inflamed these vessels throw out- lymph, but most abundantly on the surface, where swelling can take place most readily, and this, raising the fibrous covering, drags out the vessels and nuclei somewhat from the bony canals, so that when these latter resume their normal functions they transform the lymph into a bony material. This is the explanation of the development of most of these bony swellings. Where sinews are attached to bones, undue traction upon them tends equally to draw out the vessels and nuclei from the surface and to build up new bony tissue, while earthy salts are at the same time deposited in the substance of the tendon to some distance from the attached end. Spavins are bony de- posits on the antero-internal aspect of the lower part of the hock joint, where the great strain and compression come in rapid paces and in heavy draught. The joint is here pro- vided with an extra tier of bones and two ad- ditional layers of elastic cartilage to ward off injury ; but too often these prove insufficient ; the nutrition in the small bones and on their surfaces is deranged; lymph is exuded, and finally consolidates two or more of the small bones into one solid mass, and abolishes the slight gliding movements and resiliency natu- rally resident in the joints between them. Then if the inflammation is allowed to subside, the new structure becomes firmly consolidated, and lameness disappears. Spavins occur main- ly in joints that are narrow at their lower part, alike when viewed from before backward and from side to side, in overworked young horses, and in such as suffer from impaired health' faulty nutrition, or rheumatic taint. The swelling is generally best seen by standing about two feet to one side of the shoulder and looking across the lower part of the inner side of the joint. It should also be compared with that of the opposite limb, examining with eye and hand. The sudden catching up of the limb, or the imperfect bending of it in pro- gression, the stiff awkward movement in turn- ing, and the improvement in most cases after the animal has been driven for some distance, are familiar to every horseman. In the early stages of spavin with heat and tenderness, soothing measures should be adopted to sub- due inflammation and check deposit, thereby obviating the danger of fixing the joint. Hot fomentations, cold wet bandages, or astringent and arnica lotions, with a dose of physic and rest, are often sufficient, though if lameness is very great a high-heeled shoe will keep the joint easier. Later, when local inflammation has greatly moderated, active blistering and rest may remove the remaining irritation and secure consolidation of the exudate. As a blister, Spanish flies or iodide of mercury (one part to four of lard) will usually serve a good purpose. W T hen there is little or no external swelling or tenderness, but ulcerntion of the opposing surfaces of the small bones in the in- terior of the joint, nothing succeeds so well as firing followed by a long rest. Splints have a similar origin with spavins, but appear on the inner side of the shank bones of the fore limbs, as being nearest the centre of gravity, and the point where concussion especially tells. They usually begin on the inner splint bone, which extends from the knee down for about three fourths of the length of the canon. Inflamma- tion is set up, and the resulting exudate be- coming ossified usually binds the two bones together and remains as a permanent enlarge- ment, but without inducing lameness after it is consolidated throughout. But if the animal is kept at work, renewed injury is inevitable ; the structures being now soft, irritable, and susceptible, new layers of lymph continue to be exuded and consolidated into bone, and thus a splint, like a spavin, may increase to almost any size. While thus growing lameness is al- most necessarily present, and is greatly aggra- vated by trotting on hard ground, whereas it may not be shown at all on a soft surface. By standing in front of the patient, the enlarge- ment on the inner side of the limb is eadly seen, and by passing the finger or thumb down the slight groove between the shank bone and the splint, it is distinctly felt. It is usually warm and tender. Splints are treated exactly like spavins, by rest and soothing applications in the early stages, followed by blisters and even firing. In both the recent deposit which is still soft may be largely removed, but old standing bony enlargements are permanent. In each the lameness is often greatly aggra-