SPECIAL REPORT ON DISEASES OF CATTLE TEXT

growing plants, and in most of our cereals and grasses makes up a large proportion of the ashes of the burned plant. It is found in the soluble form in combination as silicate of potash, but at times is displaced by oxalic or other acid and then appears as gritty, sandy particles in the stem. This gritty, insoluble silica is especially noticeable among the horsetails (_EquisetacÊceÊ_), bamboos, and sedges. The per cent of silica in the ash of several common fodder plants is given below: _Silica in ash of various fodder plants._ Ash of-- Silica. _Per cent._ Wheat straw 67.6 Oats and husk 38.6 Oat straw 35.4 Barley straw 73.1 Rye straw 64.4 Rye-grass hay 64.57 Wheat chaff 81.2 Oat chaff 59.9 Barley awn 70.7 It is only soluble silica that is taken up into the system, and it is in this form (usually as silicate of potash or soda) that it enters the urine, but all that is wanted to precipitate it in crystalline form as a gritty sand is the presence of oxalic or other acid having a stronger affinity for its base (potash or soda). Other conditions, however, enter largely into the causation of stone, or gravel. A high density of urine resulting from a highly saturated condition is often present for a length of time without any precipitation of solid materials. Urea and carbonates may be present in excess, the feed may be given dry, and drinking water may be deficient in quantity without any deposition of stone or gravel. In such cases, the presence of noncrystalline organic matter in the urine becomes an exciting cause. Rainey and Ord have shown experimentally that colloid (noncrystallizable) bodies like mucus, epithelial cells, albumin, pus, blood, hyaline casts of the kidney tubes, etc., not only determine the precipitation of crystallizable salts from a strong solution, but they determine the precipitation in the form of globular masses, or minute spheres, which, by further similar accessions, become stones, or calculi, of various sizes. The salts that are deposited by mere chemical reaction without the intervention of colloids appear in the form of sharply defined angular crystals, and hence the rough, jagged crystals of oxalate of lime or ammonia-magnesium phosphate. Heat intensifies the action of the colloids in causing precipitation of the dissolved salts, so that the temperatures of the kidneys and bladder constitute favorable conditions. Colloids that are undergoing decomposition are also specially powerful, so that the presence of bacteria or fungi causing fermentation is an important factor. In looking, therefore, for the immediate causes of urinary calculi we must accord a high place to all those conditions which determine the presence of excess of mucus, albumin, pus, blood, kidney casts, blood-coloring matter, etc., in the urine. A catarrhal inflammation of the pelvis of the kidney, of the ureter, or of the bladder, generating excess of mucus or pus; inflammation of the kidneys, causing the discharge of blood, albumin, or hyaline casts into the urinary passages; inflammation of the liver, lungs, or other distant organ, resulting in the escape of albumin in the urine; disorders of the liver or of the blood-forming functions, resulting in hematuria or hemoglobinuria; sprains or other injuries to the back, or disease of the spinal marrow, which cause the escape of blood with the urine; the presence in the bladder of a bacterial ferment, which determines the decomposition of the mucus and urea, the evolution of ammonia and the consequent destruction of the protecting cellular (epithelia) lining of the bladder, or the irritation caused by the presence of an already formed calculus, may produce the colloid or uncrystallizable body that proves so effective in the precipitation of stone or gravel. It has long been known that calculi almost invariably form around any foreign body introduced into the kidney or bladder, and I have seen a large, calculous mass surrounding a splinter of an arrow that had penetrated and broken off in the body of a deer. The explanation is now satisfactory--the foreign body carries in with it bacteria, which act as ferments upon the urine and mucus in addition to the mechanical injury caused by its presence. If such a body has been introduced through the solid tissues, there is, in addition, the presence of the blood and lymph derived from the wounded structures. CLASSIFICATION OF URINARY CALCULI. Urinary calculi are most conveniently divided according to the locality in which they are found. Thus we find first renal calculi, formed in the kidney (Pl. XI, fig. 1), and which for cattle must be again divided into calculi of the uriniferous tubes and calculi of the pelvis. The second class are named ureteral calculi because they are found in the duct leading from the kidney to the bladder (ureter). The third class are the vesical calculi, from the bladder or vesicle in which they are found. The fourth class are the urethral calculi, and are found in the duct leading outward from the bladder through the penis (urethra). The fifth and last class are the preputial calculi, since they are found within the sheath of the penis (prepuce). Calculi may also be classed according to their chemical composition and this has the advantage of suggesting the special cause of each as found in the feed, water, soil, or general conditions of health. This classification affords no guide to their location or symptoms, as calculi of the same chemical composition may be formed at any part of the urinary passages, as those formed in the kidney may pass on through all the various passages outward, unless it is found at any point of their progress that they have grown so large that the passage will not admit them. The following are among the concretions found in the various parts: (1) _Coralline calculi._--These are of a dull-white color and irregular surface, like coral. They are made up of hard and resistant layers evenly deposited around a central nucleus. (Pl. XI, fig. 3.) Their specific gravity is 1,760, water being 1,000, and they contain 74 per cent of carbonate of lime with some carbonate of magnesia, organic matter, and a trace of carbonate of iron. Yellowish-white, smooth, round calculi of the same chemical composition are met with. (2) _Pearly calculi._--These are more frequent than the first-named variety. They are very hard and smooth on the surface, reflecting a play of various colors after the fashion of a pearl. This peculiarity appears to be caused by the thinness and semitransparency of the supposed layers. They have a specific gravity of 2,109 to 2,351, and nearly the same chemical composition as the coralline variety. Golding Bird found a specimen of this kind formed of carbonate of lime and organic matter only. (3) _Green calculi_ (_metalloid calculi_).--These are usually small and numerous, as they are exceedingly common. They are of a very hard consistency, and have a clear-polished, greenish surface of almost metallic brilliancy. They have a specific gravity of 2.301 and a composition almost identical with the second variety. (4) _White calculi._--Pure white, smooth, lustrous calculi are rare. They have a specific gravity of 2.307, and contain as much as 92 per cent of carbonate of lime with carbonate of magnesia and organic matter. (5) _Ammonio-magnesium calculi._--These are of a grayish color and a very rough, crystalline surface, which proves very irritating to the mucous membrane. They have a specific gravity of 1.109 to 1.637, and are composed chiefly of ammonio-magnesium phosphate, oxalate of lime, and organic matter, with a little carbonate of lime and magnesia. (6) _Siliceous calculi._--These are clear, smooth, and hard, and usually spherical. They have a specific gravity of 1.265 to 1.376, and contain 57 per cent of silica with carbonates of iron and magnesia, organic matter, and traces of iron. In other specimens of siliceous calculi there was a specific gravity of 3.122, and there was 79 to 85 per cent of carbonate of lime together with carbonate of magnesia, and iron, silica, and organic matter. Others are almost exclusively made of silica. (7) _Oxalate of lime calculi_ (_mulberry calculi_) (Pl. XI, fig. 2).-- These are characterized by their extremely rough, angular surface, formed by the octahedral crystals of oxalate of lime. Their specific gravity may be 3.441, and they contain oxalate of lime to the extent of 81 per cent, together with carbonates of lime and magnesia and organic matter. (8) _Gravel_ (_pultaceous deposits_).--Simple crystals may be met with at any point from the kidneys to the external opening at the end of the prepuce (sheath), and they may appear singly, as crystals, or they may accumulate in masses of fine spherical crystals almost like dirty powdered chalk suspended in water. In the ox this is especially common as a collection in the sheath, distending that into a soft, doughy swelling. FORMS OF CALCULI IN DIFFERENT SITUATIONS. Apart from the rough crystalline surfaces of the calculi of oxalate of lime and ammonio-magnesium phosphate, the general tendency is to a smooth, round outline. At times, however, they show more or less flattening with rounded angular edges, caused by the contact and mutual friction of two calculi. Sometimes two or more stones lying together become united into one by a new external deposit, and the resulting mass then shows rounded swellings on opposite sides. The large calculi occupying the pelvis of the kidneys usually show a central part having the outline of the main cavity of the pelvis and two or more projections that have been molded into the corresponding branches or channels which lead to corresponding lobes of the kidney. In winter and spring small concretions in the form of plates are often met with in the branches of the pelvis, having been formed and molded in the confined space between the projecting papilla and the surrounding cuplike branch of the pelvis. Finally, the pulplike deposits in the sheath and elsewhere are made up of globular masses, individually so small as to be often practically microscopic. STONE IN THE KIDNEY (RENAL CALCULI). [Pl. XI, fig. 1.] In an animal leading the quiet, uneventful life of the ox, stones of large size may be present in the kidney without producing any disorder appreciable to the people about him. In cattle fattened on dry feed in winter, on the magnesian limestone of New York, it is exceptional to find the substance of the kidney free from calculi about the size of a grain of wheat or less, and standing out as white objects in the general red of the cut surface of the organ. Similarly around the papillÊ in the cuplike arms of the pelvis we find minute, flattened or more or less rounded, yellowish-white concretions. Even the large concretions may prove apparently harmless. I have a calculus several ounces in weight which filled the entire pelvis of the kidney, that was found by accident in a fat carcass while being dressed. In work oxen, however, such concretions may give rise to symptoms of kidney disease, such as stiffness of the loins, shown especially in the acts of rising or turning, weakness of the hind parts when set to pull a heavy load, an irritability of the kidneys, shown by the frequent passage of urine in small quantity, tenderness of the loins, shown when they are pinched or lightly struck, and it may be the passage of blood or minute gritty masses with the urine. If the attack is severe, what is called "renal colic" (kidney colic) may be shown by frequent uneasy shifting of the hind limbs, shaking or twisting of the tail, looking around at the flanks, and lying down and rising again at short intervals without apparent cause. The frequent passage of urine, the blood or gritty masses contained in it, and perhaps the hard, stony cylinders around the tufts of hair of the sheath, show that the source of the suffering is the urinary organs. In bad cases active inflammation of the kidneys may set in. (See "Nephritis," p. 123.) URETERAL CALCULI. These are small stones which have passed from the pelvis of the kidney into the canal (ureter) leading from the kidney to the bladder, but, being too large to pass on easily, have blocked that canal and forced the urine back upon the kidney. The result is the production of symptoms more violent than in renal calculi, though not varying, save in intensity, from those of renal colic. In case of complete and unrelieved obstruction, the secretion of the kidney on that side is entirely abolished, and it becomes the seat of passive congestion, and it may even be absorbed in greater part or as a whole, leaving only a fibrous sac containing fluid with a urinous odor. In small cattle, in which the oiled hand introduced into the last gut may reach the affected part, the distended ureter may be felt as a tense, elastic cord, extending forward from the point of obstruction on the lateral wall of the pelvis and beneath the loins toward the kidney. If relief is obtained by the onward passage of the stone a free flow of urine usually follows, in the midst of which may often be found gritty masses. If the outlets from both kidneys are similarly blocked the animal becomes poisoned by the retention in the blood of the elements of the urine, and by their reabsorption after secretion. _Treatment of renal and ureteral calculi._--Treatment is not very successful, as only the smallest calculi can pass through the ureter and enter the bladder, and even if they should do so they are liable to a progressive increase there, so that later they may cause the symptoms of stone in the bladder. Fortunately, ordinary dairy, growing, or fattening cattle rarely show evident symptoms of illness, and even though they do so they can usually be fattened and slaughtered before the health is seriously impaired. In work oxen the case is different, and acute symptoms may develop, but even then the animal may often be fitted for the butcher. When treatment is demanded it is primarily soothing and antispasmodic. Fomentations with warm water over the loins should be persisted in without intermission until relief has been secured. The soothing effect on the kidney will often relieve inflammation and irritation, should the stone be in that situation, while if in the ureter the warm fomentations will at once soothe irritation, relax spasm of the muscular coat of the canal, and favor an abundant secretion from the kidney, which, pressing on the obstructing stone, may slowly push it on into the bladder. Large doses of laudanum (2 ounces) or of solid extract of belladonna (2 drams) will not only soothe the pain but relax the spasm and favor the onward passage of the calculus. The animal should be encouraged to drink large quantities of cool water to favor the free secretion of a very watery urine, which will not only serve to obviate irritation and continued deposit caused by a highly concentrated urine, but will press the stone onward toward the bladder, and even in certain cases will tend to disintegrate it by solution of some of its elements, and thus to favor its crumbling and expulsion. This is a principle which must never be lost sight of in the treatment of calculi. The immersion of the stone in a liquid of a lower specific gravity than that in which it has formed and grown tends to dissolve out the more soluble of its component parts, and thus to destroy its density and cohesion at all points, and thereby to favor its complete disintegration and expulsion. This explains why cattle taken from a herd on magnesian limestone in spring, after the long, dry feeding of winter, usually have renal calculi, while cattle from the same herd in the fall, after a summer's run on a succulent pasture, are almost always free from concretions. The abundance of liquid taken in the green feed and expelled through the kidneys and the low density or watery nature of the urine have so opened the texture and destroyed the density of the smaller stones and gravel that they have all been disintegrated and removed. This, too, is the main reason why benefit is derived from a prolonged stay at mineral springs by the human victims of gravel. If they had swallowed the same number of quarts of pure water at home and distributed it at suitable times each day, they would have benefited largely without a visit to the springs. It follows from what has been just said that a succulent diet, including a large quantity of water (gruels, sloppy mashes, turnips, beets, potatoes, apples, pumpkins, ensilage, succulent grasses), is an important factor in the relief of the milder forms of stone and gravel. _Prevention._--Prevention of calculus especially demands this supply of water and watery rations on all soils and in all conditions in which there is a predisposition to the disease. It must also be sought by attempts to obviate all those conditions mentioned above as causative of the malady. Sometimes good rain water can be furnished in limestone districts, but putrid or bad-smelling rain water is to be avoided as probably more injurious than that from the limestone. Unsuccessful attempts have been made to dissolve calculi by alkaline salts and mineral acids, respectively, but their failure as a remedy does not necessarily condemn them as preventives. One dram of caustic potash or of hydrochloric acid may be given daily in the drinking water. In diametrically opposite ways these attack and decompose the less soluble salts and form new ones which are more soluble and therefore little disposed to precipitate in the solid form. Both are beneficial as increasing the secretion of urine. In cases in which the diet has been too highly charged with phosphates (wheat bran, etc.), these aliments must be restricted and water allowed ad libitum. If the crystals passed with the urine are the sharp angular (octahedral) ones of oxalate of lime, then the breathing should be made more active by exercise, and any disease of the lungs subjected to appropriate treatment. If the crystals are triangular prisms of ammonia-magnesium phosphate or starlike forms with feathery rays, the indications are to withhold the feed or water that abounds in magnesia and check the fermentation in the urine by attempts to destroy its bacteria. In the latter direction plenty of pure-water diuretics, and a daily dose of oil of turpentine in milk, or a dose thrice a day of a solution containing one-tenth grain each of biniodid of mercury and iodid of potassium would be indicated. In considering the subject of prevention, it must never be forgotten that any disease of a distant organ which determines the passage from the blood into the urine of albumin or any other colloid (uncrystallizable) body is strongly provocative of calculus, and should, if possible, be corrected. Apart from cases from geological formation, faulty feeding, and other causes, the grand preventive of calculus is a long, summer's pasturage of succulent grasses, or in winter a diet of ensilage or other succulent feed. The calculi formed in part of silica demand special notice. This agent is secreted in the urine in the form of silicate of potash and is thrown down as insoluble silica when a stronger acid displaces it by combining with the potash to its exclusion. In cases of siliceous calculi, accordingly, the appropriate chemical prevention is caustic potash, which being present in the free state would attract to itself any free acid and leave the silica in its soluble condition as silicate of potash. STONE IN THE BLADDER (VESICAL CALCULUS, OR URETHRAL CALCULUS). Stone in the bladder may be of any size, but in the ox does not usually exceed half an inch in diameter. There may, however, be a number of small calculi; indeed, they are sometimes so small and numerous as to form a