Chapter VII: Part 7

In bloody urine albumin is always present as an important constituent of the blood, and in congested and inflamed kidneys it is present as a part of the inflammatory exudate. Apart from these, albumin in the urine represents in different cases a variety of diseased conditions of the kidneys or of distant organs. Among the additional causes of albuminuria may be named: (1) An excess of albumin in the blood (after easy calving with little loss of blood and before the secretion of milk has been established, or in cases of sudden suppression of the secretion of milk); (2) under increase of blood pressure (after deep drinking, after doses of digitalis or broom, after transfusion of blood from one animal to another, or in disease of the heart or lungs causing obstruction to the flow of blood from the veins); (3) after cutting (or disease) of the motor nerves of the vessels going to the kidneys, causing congestion of these organs; (4) violent exertion, hence long drives; the same happens with violent, muscular spasms, as from strychnia poisoning, lockjaw, epilepsy, and convulsions; (5) in most fevers and extensive inflammations of important organs, like the lungs or liver, the escape of the albumin being variously attributed to the high temperature of the body and disorder of the nerves, and to resulting congestion and disorder of the secreting cells of the kidneys; (6) in burns and some other congested states of the skin; (7) under the action of certain poisons (strong acids, phosphorous, arsenic, Spanish flies, carbolic acid, and those inducing bloody urine); (8) in certain conditions of weakness or congestion of the secreting cells of the kidneys, so that they allow this element of the blood to escape; (9) when the feed is entirely wanting in common salt, albumin may appear in the urine temporarily after a full meal containing an excess of albumin. It can also be produced experimentally by puncturing the back part of the base of the brain (the floor of the fourth ventricle close to the point the injury to which causes sugary urine). In abscess, tumor, or inflammation of the bladder, ureter, or urethra the urine is albuminous.

It follows, therefore, that albumin in the urine does not indicate the existence of any one specific disease, and except when from weakness or loss of function of the kidney cells, it must be looked on as an attendant on another disease, the true nature of which we must try to find out. These affections we must exclude one by one until we are left to assume the noninflammatory disorder of the secreting cells of the kidney. It is especially important to exclude inflammation of the kidney, and to do this may require a microscopic examination of the sediment of the urine and the demonstration of the entire absence of casts of the uriniferous tubes. (See "Nephritis," p. 123.)

To detect albumin in the urine, the suspected and frothy liquid must be rendered sour by adding a few drops of nitric acid and then boiled in a test tube. If a solid precipitate forms, then a few more drops of nitric acid should be added, and if the liquid does not clear it up it is albumin. A precipitate thrown down by boiling and redissolved by nitric acid is probably phosphate of lime.

_Treatment._--Treatment is usually directed to the disease on which it is dependent. In the absence of any other recognizable disease, mucilaginous drinks of boiled flaxseed, slippery elm, or gum may be given, tannic acid, one-half dram twice daily, and fomentations or even mustard poultices over the loins. When the disease is chronic and there is no attendant fever (elevation of temperature), tonics (hydrochloric acid, 6 drops in a pint of water; phosphate of iron, 2 drams, or sulphate of quinin, 2 drams, repeated twice daily) may be used. In all cases the patient should be kept carefully from cold and wet, a warm, dry shed, or in warm weather a dry, sunny yard or pasture being especially desirable.

SUGAR IN URINE (DIABETES MELLITUS).

This is a frequent condition of the urine in parturition fever, but as a specific disease, associated with deranged liver or brain, it is practically unknown in cattle. As a mere attendant on another disease it demands no special notice here.

INFLAMMATION OF THE KIDNEYS (NEPHRITIS).

This has been divided according as it affects the different parts of the kidneys, as: (1) Its fibrous covering (perinephritis); (2) the secreting tissue of its outer portion (parenchymatous); (3) the connective tissue (interstitial); (4) the lining membrane of its ducts (catarrhal); and (5) its pelvis or sac receiving the urine (pyelitis). It has also been distinguished according to the changes that take place in the kidney, especially as seen after death, according to the quantity of albumin in the urine, and according as the affection is acute or chronic. For the purpose of this work it will be convenient to consider these as one inflammatory disease, making a distinction merely between the acute and the chronic or of long standing.

The _causes_ are in the main like those causing bloody urine, such as irritant and diuretic plants, Spanish flies applied as a blister or otherwise, exposure to cold and wet, the presence of stone or gravel in the kidneys, injuries to the back or loins, as by riding one another, the drinking of alkaline or selenitic water, the use of putrid, stagnant water, of that containing bacteria and their products, the consumption of musty fodder, etc. (See "Hematuria," p. 119.)

The length of the loins in cattle predisposes these parts to mechanical injury, and in the lean and especially in the thin, working ox the kidney is very liable to suffer. In the absence of an abundance of loose, connective tissue and of fat, the kidneys lie in close contact with the muscles of the loins, and any injury to them may tend to stretch the kidney and its vessels, or to cause its inflammation by direct extension of the disease from the injured muscle to the adjacent kidney. Thus, under unusually heavy draft, under slips or falls on slippery ground, under sudden unexpected drooping or twisting of the loins from missteps or from the feet sinking into holes, under the loading and jarring of the loins when animals ride one another in cases of "heat," the kidneys are subject to injury and inflammation. A hard run, as when chased by a dog, may be the occasion of such an attack. A fodder rich in nitrogenous or flesh-forming elements (beans, peas, vetches (_Vicia sativa_), and other leguminous plants) has been charged with irritating the kidneys through the excess of urea, hippuric acid, and allied products eliminated through these organs and the tendency to the formation of gravel. It seems, however, that these feeds are most dangerous when partially ripened and yet not fully matured, a stage of growth at which they are liable to contain ingredients irritating to the stomach and poisonous to the brain, as seen in their inducing so-called "stomach staggers." Even in the poisoning by the seeds of ripened but only partially cured rye grass (_Lolium perenne_), and darnel (_Lolium temulentum_), the kidneys are found violently congested with black blood; also, in the indigestions that result from the eating of partially ripened corn or millet some congestion of the kidneys is an attendant phenomenon.

Cruzel says that the disease as occurring locally is usually not alone from the acrid and resinous plants charged with inducing hematuria, but also from stinking camomile (_Anthemis cotula_) and field poppy when used in the fresh, succulent condition; also from the great prevalence of dead caterpillars on the pasture, or from dead Spanish flies in the stagnant pools of water. The fresh plants are believed to be injurious only by reason of a volatile oil which is dissipated in drying. In the case of the stagnant water it may be questioned whether the chemical products of the contained ferments (bacteria) are not more frequently the cause of the evil than the alleged Spanish flies, though the latter are hurtful enough when present.

Inflammation of the kidneys may further be a form or an extension of a specific contagious disease, such as erysipelas, rinderpest, septicemia, or even of poisoning by the spores of fungi. Rivolta reports the case of a cow with spots of local congestion and blood staining in the kidney, the affected parts being loaded with bacteria. Unfortunately he neither cultivated the bacteria nor inoculated them, and thus the case stands without positive demonstration that they were the cause of disease.

In certain cases the _symptoms_ of nephritis are very manifest, and in others so hidden that the existence of the affection can be certainly recognized only by a microscopic examination of the urine. In violent cases there is high fever, increase of the body temperature to 103∞ F. and upward; hurried breathing, with a catching inspiration; accelerated pulse; dry, hot muzzle; burning of the roots of the horns and ears; loss of appetite; suspended rumination; and indications of extreme sensitiveness in the loins. The patient stands with back arched and hind legs extended backward and outward, and passes water frequently, in driblets, of a high color and specific gravity, containing albumin and microscopic casts. (Pl. XI, fig. 5.) When made to move, the patient does so with hesitation and groaning, especially if turned in a narrow circle; when pinched on the flank just beneath the lateral bony processes of the loins, especially on that side on which the disease predominates, it flinches and groans. If the examination is made with oiled hand introduced through the last gut (rectum), the pressure upward on the kidneys gives rise to great pain and to efforts to escape by moving away and by active contractions of the rectum for the expulsion of the hand. Sometimes there is a distinct swelling over the loins or quarter on one or both sides. In uncastrated males the testicle on the affected side is drawn up, or is alternately raised and dropped. In all there is a liability to tremors of the thigh on the side affected.

In some severe cases colicky pains are as violent as in the worst forms of indigestion and spasms of the bowels. The animal frequently shifts from one hind foot to the other, stamps, kicks at the belly, frequently looks anxiously at its flank, moans plaintively, lies down and quickly gets up again, grinds its teeth, twists its tail, and keeps the back habitually arched and rigid and the hind feet advanced under the belly. The bowels may be costive and the feces glistening with a coat of mucus, or they may be loose and irritable, and the paunch or even the bowels may become distended with gas (bloating) as the result of indigestion and fermentation. In some animals, male and female alike, the rigid, arched condition of the back will give way to such undulating movements as are sometimes seen in the act of coition.

The disease does not always appear in its full severity; for a day, or even two, however, there may be merely loss of appetite, impaired rumination, a disposition to remain lying down, yet when the patient is raised it manifests suffering by anxiously looking at the flanks, shifting or stamping of the hind feet, shaking of the tail, and attempts to urinate, which are either fruitless or lead to the discharge of a small quantity of high-colored or perhaps bloody urine.

In some recent slight cases, and in many chronic ones, these symptoms may be absent or unobserved, and an examination of the urine is necessary to reach a safe conclusion. The urine may contain blood, or it may be cloudy from contained albumin, which coagulates on heating with nitric acid (see "Albuminuria," p. 121); it may be slightly glairy from pus, or gritty particles may be detected in it. In seeking for casts of the uriniferous tubes, a drop may be taken with a fine tube from the bottom of the liquid after standing, and examined under a power magnifying 50 diameters. If the fine, cylindroid filaments are seen they may then be examined with a power of 200 or 250 diameters. (Pl. XI, fig. 5.) The appearance of the casts gives some clue to the condition of the kidneys. If made up of large, rounded or slightly columnar cells, with a single nucleus in each cell (epithelial), they imply comparatively slight and recent disease of the kidney tubes, the detachment of the epithelium being like what is seen in any inflamed mucous surface. If made up largely of the small, disk-shaped and nonnucleated red blood globules, they imply escape of blood, and usually a recent injury or congestion of the kidney--it may be from sprains, blows, or the ingestion of acrid or diuretic poisons. If the casts are made of a clear, waxy, homogeneous substance (hyaline), without any admixture of opaque particles, they imply an inflammation of longer standing, in which the inflamed kidney tubules have been already stripped of their cellular (epithelial) lining. If the casts are rendered opaque by the presence of minute, spherical granular cells, like white blood globules, it betokens active suppuration of the kidney tubes. In other cases the casts are rendered opaque by entangled earthy granules (carbonate of lime), or crystals of some other urinary salts. In still other cases the casts entangle clear, refrangent globules of oil or fat, which may imply fatty degeneration of the kidneys or injury to the spinal cord. The presence of free pus giving a glairy, flocculent appearance to the urine is suggestive of inflammation of the urinary pouch at the commencement of the excretory duct (pelvis of kidney) (Pl. IX, fig. 1), especially if complicated with gritty particles of earthy salts. This condition is known as pyelitis. In the chronic cases swelling of the legs or along the lower surface of chest or abdomen, or within these respective cavities, is a common symptom. So, also, stupor or coma, or even convulsions, may supervene from the poisonous action of urea and other waste or morbid products retained in the blood.

_Treatment._--In the treatment of acute nephritis the first consideration is the removal of the cause. Acrid or diuretic plants in the feed must be removed, and what of this kind is present in the stomach or bowels may be cleared away by a moderate dose of castor or olive oil; extensive surfaces of inflammation that have been blistered by Spanish flies must be washed clean with soapsuds; sprains of the back or loins must be treated by soothing fomentations or poultices or by a fresh sheepskin with its fleshy side applied on the loins, and the patient must be kept in a narrow stall in which it can not turn even its head. The patient must be kept in a warm, dry building, so that the skin may be kept active rather than the kidneys. Warm blanketing is equally important, or even mustard poultices over the loins will be useful. Blisters of Spanish flies, turpentine, or other agent which may be absorbed and irritate the kidneys must be avoided. The active fever may be checked by 15 drops tincture of aconite every four hours or by one-third ounce of acetanilid. If pain is very acute, 1 ounce of laudanum or 2 drams of solid extract of belladonna will serve to relieve. When the severity of the disease has passed, a course of tonics (quinin, 2 drams, or gentian powder, 4 drams, daily) may be given. Diuretics, too, may be given cautiously at this advanced stage to relieve dropsy and give tone to the kidneys and general system (oil of turpentine, 2 teaspoonfuls; bicarbonate of soda, 1 teaspoonful, repeated twice a day). Pure water is essential, and it should not be given chilled; warm drinks are preferable.

In the chronic forms of kidney inflammation the same protection against cold and similar general treatment are demanded. Tonics, however, are important to improve the general health (phosphate of iron, 2 drams; powdered nux vomica, 20 grains; powdered gentian root, 4 drams, daily). In some instances the mineral acids (nitric acid, 60 drops, or nitrohydrochloric acid, 60 drops, daily) may be used with the bitters. Mustard applied to the loins in the form of a thin pulp made with water and covered for an hour with paper or other impervious envelope, or water hotter than the hand can bear, or cupping, may be resorted to as a counterirritant. In cupping, shave the loins, smear them with lard, then take a narrow-mouthed glass, expand the air within by smearing its interior with a few drops of alcohol, setting it on fire and instantly pressing the mouth of the vessel to the oiled portion of the skin. As the air within the vessel cools it contracts, tending to form a partial vacuum, and the skin, charged with blood, is strongly drawn up within it. Several of these being applied at once, a strong derivation from the affected kidneys is obtained. In no case of inflamed or irritable kidney should Spanish flies or oil of turpentine be used upon the skin.

PARASITES OF THE KIDNEY.

As the kidney is the visual channel by which the bacteria leave the system, this organ is liable to be implicated when microphytes exist in the blood, and congestions and blood extravasions are produced. In anthrax, southern cattle fever (Texas fever), and other such affections bloody urine is the consequence. Of the larger parasites attacking the kidney may be specially named the cystic form of the echinococcus tapeworm of the dog, the cystic form of the unarmed or beef tapeworm of man, the diving bladderworm--the cystic form of the marginate tapeworm of the dog, and the giant strongyle-- the largest of the roundworms. These give rise to general symptoms of kidney disease, but the true source of the trouble is likely to be detected only if the heads or hooklets of the tapeworm or the eggs of the roundworm are found on microscopical examination of the urine.

TUMORS OF THE KIDNEY (HYPERTROPHY OR ATROPHY).

The kidney may be the seat of cancerous or simple tumors, and it may be unnaturally enlarged or reduced in size, but though there may be signs of urinary disorder the true nature of the disease is seldom manifest until after death. The passing of blood and of large multi-nucleated cells in the urine (to be detected under the microscope) may betray the existence of an ulcerated cancer of the kidney. The presence of cancerous enlargement of (superficial) lymphatic glands may further assist and confirm the decision.

RETENTION OF URINE.

Inability to pass urine may come from any one of three conditions--first, spasm of the neck of the bladder; second, paralysis of the body of the bladder; third, obstruction of the channel of outlet by a stone (calculus) (see Pl. XI) or other obstacle.

In _spasm of the neck of the bladder_ the male animal may stand with the tail slightly raised and making rhythmical contractions of the muscle beneath the anus (accelerator urinÊ) (see Pl. IX, fig. 2), but without passing a drop of liquid. In the female the hind legs are extended, widely parted, and the back is arched as if to urinate, but the effort is vain. If the oiled hand is introduced into the rectum or vagina in the early stages of the affection, the bladder may be felt beneath partially filled, but not overdistended with liquid, and its neck or mouth firm and rigid. In the more advanced stages of the affection the organ is felt as a great, tense, elastic bag, extending forward into the abdomen. In this condition the overdistended muscular coat of the bladder has lost its power of contraction, so that true paralysis has set in, the muscle closing the mouth of the sac alone retaining its contractile power.

In _paralysis of the body of the bladder_ attention is rarely drawn to the urinary disorder until the bladder has been distended to full repletion and is almost ready to give way by rupture and to allow the escape of the contained liquid into the abdomen. Overdistention is the most common cause of the paralysis, yet it may occur from inflammation of the muscular wall of the bladder, or even from injury to the terminal part of the spinal marrow. In this last condition, however, the tail is liable to be powerless, and the neck of the bladder may also be paralyzed, so that the urine dribbles away continuously.

_Causes._--Among the causes of spasm of the neck of the bladder may be named the lodgment of small stones or gravel, the feeding on irritant diuretics (see "Bloody urine," p. 119, or "Nephritis," p. 123), the enforced retention of urine while at work or during a painful or difficult parturition. The irritation attendant on inflammation of the mucous membrane of the bladder may be a further cause of spasms of the neck, as may also be inflammation of the channel (urethra) back of the neck. Extensive applications of Spanish flies to the skin, the abuse of diuretics, and the occurrence of indigestion and spasms of the bowels are further causes. So long as spasmodic colic is unrelieved, retention of water from spasm of the neck of the bladder usually persists.

_Treatment._--Treatment depends largely on the cause. In indigestion the irritant contents of the bowels must be got rid of by laxatives and injections of warm water; Spanish-fly blisters must be washed from the surface; a prolonged and too active exertion must be intermitted. The spasm may be relaxed by injecting one-half ounce of solid extract of belladonna in water into the rectum or by a solution of tobacco. Chloroform or ether may be given by inhalation, or chloral hydrate (1 ounce) may be given in water by the mouth. Fomentations of warm water may be made over the loins and between the thighs, and the oiled hand inserted into the rectum may press moderately on the anterior part of the bladder, which can be felt as an elastic fluctuating bag of an oval shape just beneath.

All other measures failing, the liquid must be drawn off through a tube (catheter). This is, however, exceedingly difficult, alike in male and female, and we can not expect an amateur to succeed in accomplishing it. In the cow the opening into the bladder is found in the median line of the floor of the generative entrance, about 4 inches in front of the external opening, but it is flanked on either side by a blind pouch, into which the catheter will pass, in ninety-nine cases out of a hundred, in the hands of any but the most skilled operator. In the bull or steer the penis, when retracted into its sheath, is bent upon itself like the letter S, just above the scrotum and testicles (see Pl. IX, fig. 2), and unless this bend is effaced by extending the organ forward out of its sheath it is quite impossible to pass a catheter beyond this point. When, however, by the presentation of a female, the animal can be tempted to protrude the penis, so that it can be seized and extended, or when it can be manipulated forward out of the sheath, it becomes possible to pass a catheter of small caliber (one-third inch or under) onward into the bladder. Youatt advised laying open the sheath so as to reach and extend the penis, and others have advocated opening the urethra in the space between the thighs or just beneath the anus, but such formidable operations are beyond the stock owner. The incision of the narrow urethra through the great thickness of muscular and erectile bleeding tissue just beneath the anus is especially an operation of extreme delicacy and difficulty. Drawing the liquid through the tube of an aspirator is another possible resort for the professional man. The delicate needle of the aspirator is inserted in such cases through the floor of the vagina and upper wall of the bladder in the female, or through the floor of the rectum (last gut) and roof of the bladder in the male, or finally through the lower and back part of the abdominal wall, just in front of the bones of the pelvis (pubic bones), thence through the lower and anterior part of the bladder near its blind anterior end. After relief has been obtained the administration of belladonna in 2-dram doses daily for several days will tend to prevent a recurrence of the retention.

When the body of the bladder has become benumbed or paralyzed by overdistention, we may seek to restore its tone by doses of one-half a dram of powdered nux vomica repeated daily, and by mustard plaster applied over the loins, on the back part of the belly inferiorly, or between the thighs. Small doses (2 drams) of balsam of copaiba are sometimes useful in imparting tone to the partly paralyzed organ.

INCONTINENCE OF URINE (PALSY OF THE NECK OF THE BLADDER).

This may occur from disease or injury to the posterior part of the spinal cord or from broken back, and in these cases the tail, and perhaps the hind limbs, are liable to be paralyzed. In this case the urine dribbles away constantly, and the oiled hand in the vagina or rectum will feel the half-filled and flaccid bladder beneath and may easily empty it by pressure.

_Treatment._--Treatment is only successful when the cause of the trouble can be remedied. After these (sprains of the back, etc.) have recovered, blisters (mustard) on the loins, the lower part of the abdomen, or between the thighs may be resorted to with success. Two drams of copaiba or of solid extract of belladonna or 2 grains Spanish flies daily may serve to restore the lost tone. These failing, the use of electric currents may still prove successful.

URINARY CALCULI (STONE OR GRAVEL).

Stone or gravel consists of hard bodies mainly made up of the solid earthy constituents of the urine which have crystallized out of that liquid at some part of the urinary passage, and have remained as small particles (gravel), or have concreted into large masses (stone, calculus). (See Pl. XI, figs. 1, 2, 3.) In cattle it is no uncommon thing to find them distending the practically microscopic tubes in the red substance of the kidney, having been deposited from the urine in the solid form almost as soon as that liquid has been separated from the blood. These stones appear as white objects on the red ground formed by cutting sections of the kidney, and are essentially products of the dry feed of winter, and are most common in working oxen, which are called upon to exhale more water from the lungs and skin than are the slop-fed and inactive cows. Little water being introduced into the body with the feed and considerable being expelled with the breath and perspiration in connection with the active life, the urine becomes small in amount, but having to carry out all waste material from the tissues and the tissue-forming feed it becomes so charged with solids that it is ready to deposit them on the slightest disturbance. If, therefore, a little of the water of such concentrated urine is reabsorbed at any point of the urinary passages the remainder is no longer able to hold the solids in solution, and they are at once precipitated in the solid form as gravel or commencing stone. In cattle, on the other hand, which are kept at pasture in summer, or which are fed liberally on roots, potatoes, pumpkins, apples, or ensilage in winter, this concentrated condition of the urine is not induced, and under such circumstances, therefore, the formation of stone is practically unknown. Nothing more need be said to show the controlling influence of dry feeding in producing gravel and of a watery ration in preventing it. Calculus in cattle is essentially a disease of winter and of such cattle as are denied succulent feed and are confined to dry fodder as their exclusive ration. While there are exceptions, they are so rare that they do not invalidate this general rule. It is true that stone in the kidney or bladder is often found in the summer or in animals feeding at the time on a more or less succulent ration, yet such masses usually date back to a former period when the animals were restricted to a dry ration.

In this connection is should be noted that a great drain of water from the system by any other channel than the kidneys predisposes to the production of gravel or stone. In case of profuse diarrhea, for example, or of excessive secretion of milk, there is a corresponding diminution of the water of the blood, and as the whole quantity of the blood is thus decreased and as the urine secreted is largely influenced by the fullness of the blood vessels and the pressure exerted upon their walls from within, it follows that with this decrease of the mass of the blood and the lessening of its pressure outward there will be a corresponding decrease of urine. The waste of the tissues, however, goes on as before, and if the waste matter is passed out through the kidneys it must be in a more concentrated solution, and the more concentrated the urine the greater the danger that the solids will be deposited as small crystals or calculi.

Again, the concentrated condition of the urine which predisposes to such deposits is favored by the quantity of lime salts that may be present in the water drunk by the animal. Water that contains 20 or 30 grains of carbonate or sulphate of lime to the gallon must contribute a large addition of solids to the blood and urine as compared with soft waters from which lime is absent. In this connection it is a remarkable fact that stone and gravel in the domesticated herbivora are notoriously prevalent on many limestone soils, as on the limestone formations of central and western New York, Pennsylvania, Ohio, and Michigan; on the calcareous formations of Norfolk, Suffolk, Derbyshire, Shropshire, and Gloucestershire, in England; in Landes in France, and around Munich in Bavaria. It does not follow that the abundance of lime in the water and fodder is the main cause of the calculi, as other poisons which are operative in the same districts in causing goiter in both man and animal probably contribute to the trouble, yet the excess of earthy salts in the drinking water can hardly fail to add to the saturation of both blood and urine, and thereby to favor the precipitation of the urinary solids from their state of solution.

The known results of feeding cattle a generous or forcing ration in which phosphate of lime is present to excess adds additional force to the view just advanced. In the writer's experience, the Second Duke of Oneida, a magnificent product of his world-famed family, died as the result of a too liberal allowance of wheat bran, fed with the view of still further improving the bone and general form of the Duchess strain of Shorthorns. Lithotomy was performed and a number of stones removed from the bladder and urethra, but the patient succumbed to an inflammation of the bowels, induced by the violent purgatives given before the writer arrived, under the mistaken idea that the straining had been caused by intestinal impaction. In this case not only the Second Duke of Oneida, but the other males of the herd as well, had the tufts of hairs at the outlet of the sheath encased in hard, cylindroid sheaths of urinary salts, precipitated from the liquid as it ran over them. The tufts were in reality resolved into a series of hard, rollerlike bodies, more or less constricted at intervals, as if beaded.

When it is stated that the ash of the whole grain of wheat is but 3 per cent, while the ash of wheat bran is 7.3 per cent, and that in the case of the former 46.38 per cent of the ash is phosphoric acid, and in that of the latter 50 per cent, it can easily be understood how a too liberal use of wheat bran should prove dangerous if fed dry. The following table shows the relative proportion of ash and phosphoric acid in wheat bran and in some common farm seeds:

_Ash and phosphoric acid in bran and some common farm seeds._

--------------------+----------+-------------+---------------
Kind of grain. | Ash. | Phosphoric | Phosphoric
| |acid in ash. | acid in the
| | | entire feed.
--------------------+----------+-------------+---------------
|_Per cent_| _Per cent_ | _Per cent_
Wheat bran | 7.3 | 50 | 3.65
Wheat, grain | 3 | 46.38 | 1.3914
Oats, grain | 2.50 | 26.5 | .6625
Barley, grain | 3.10 | 39.6 | 1.2276
Bean, grain | 3.10 | 31.9 | .9864
Peas, grain | 2.75 | 34.8 | .957
Tare, grain | 3 | 36.2 | 1.086
Indian corn, grain. | 1.5 | -- | --
Rye, grain | 1.6 | 39.9 | .6384
--------------------+----------+-------------+---------------

Wheat bran, it will be observed, contains three times as much phosphoric acid as is found in any of the other grains, and four times as much as oats, beans, peas, or rye; so that if fed in excess it will readily overcharge the urine with phosphates.

There is another point to be considered, however, in estimating this danger. Wheat bran contains a far greater quantity of albuminoids and other nitrogen-containing constituents than the common grains (these being made up mainly of starch, which contains no nitrogen); and, all nitrogen-bearing products contained in the blood and tissues being expelled from the body mainly through the kidneys in the form of urea and (in cattle) hippuric acid, it follows that the excess of urea formed when such feed is consumed must load the urine with solids and bring it constantly nearer to the point of saturation, when such solids (or the least soluble of them) must be deposited.

The following table will show the relative amounts of the nitrogen-bearing products in wheat bran and some of our common grains:

_Nitrogenous matter in wheat bran and some common farm grains._

-----------------+---------------+----------------+----------------------
Kind of grain. | Albuminoids | Woody fiber | Total nitrogenous-
| (nitrogenous).| (nitrogenous.) | bearing constituents.
-----------------+---------------+----------------+----------------------
| _Per cent_ | _Per cent_ | _Per cent_
Wheat bran. | 16.1 | 8 | 24.1
Wheat, grain | 12.5 | 1.8 | 14.3
Barley, grain | 12.4 | 2.7 | 15.1
Oats, grain | 11.8 | 9.5 | 21.3
Rye, grain | 10.6 | 1.7 | 12.3
Indian corn | 10.1 | 1.7 | 11.8
-----------------+---------------+----------------+----------------------

It will be observed that, with the exception of oats, none of the grains contain more than two-thirds of the nitrogenous material present in the wheat bran, while in the case of rye and maize there is practically but one-half. Even in the case of oats the albuminoids, which are the more digestible principles, and therefore those that are the most easily and speedily converted into urea, are present only to the amount of two-thirds of that which exists in the wheat bran. With such an excess of ash, of phosphates, and of nitrogenous (urea-forming) constituents in wheat bran, its tendency to favor the formation of calculi is fully explained. It must not, however, be inferred that wheat bran is not a valuable feedstuff. The inference is only that it should be fed with an abundance of water, as a sloppy mash, or in combination with an abundance of roots, potatoes, pumpkins, or other succulent aliment.

In this connection the presence of magnesia in the feed or water must be named as favoring calculous formations in the urinary passages. The explanation is that while the phosphate of magnesia thrown out in the urine is soluble in water, the compound phosphate of ammonia and magnesia is insoluble, and, accordingly, if at any time ammonia is introduced into urine containing the phosphate of magnesia there is instantly formed the ammonio-magnesium phosphate, which is as promptly deposited in the solid form. The common source of ammonia in such cases is from decomposition of the urea in fermenting urine. In order to produce this a ferment is necessary, however, and therefore, as an additional prerequisite, the presence of bacteria, or fungi, in the urine is essential. These ferments may make their way from without along the urinary passage (urethra), and their propagation in the bladder is greatly favored by the prolonged retention of urine, as in case of spasm of the neck of the bladder or obstruction by an already existing stone. Another mode of entrance of the ferment is an unclean catheter used to draw the urine. Still another is the elimination through the kidneys of the bacteria of infectious diseases, or of such as, without producing a general infection, yet determine fermentation in the urine. The precipitation is favored not only by the production of ammonia, but also by the formation of viscid (colloid) products of fermentation. In this sense bacteria are most important factors in causing gritty deposits in the urine.

Another insoluble salt which enters largely into the composition of many urinary calculi of the ox is carbonate of lime. This is derived mainly from the lime in the feed and water and from the carbon dioxid formed by the oxidation of the organic acids in the fodder. These organic acids, being composed of carbon, hydrogen, and oxygen (without nitrogen), are resolved by the addition of oxygen into carbon dioxid (CO_{2}) and water (H_{2}O). The carbon dioxid unites with the lime in the blood to form carbonate of lime, and in this state passes into the urine. Now, carbonate of lime is soluble in water containing free or uncombined carbon dioxid, but is precipitated whenever the latter is withdrawn. It is only necessary, therefore, to have in the urine sufficient lime or other available base to unite with all the free carbon dioxid in order to bring about the precipitation of the dissolved carbonate of lime in the solid, crystallized form; hence it is that, of all sediments in the urine of herbivora, this is the most frequent and usually the most abundant.

A less common constituent of urinary calculi is the insoluble oxalate of lime. In this case the lime is derived as before from the feed or water, or both, while the oxalic acid is a product of the oxidation of organic acids of the feed, less oxygen having been used than in the formation of carbon dioxid. The final product of the complete oxidation of these acids is carbon dioxid, but when less oxygen is furnished, owing to some disease of the lungs or a disease of the nerve centers, which lessens the activity of the breathing, then oxalic acid may be produced. If this oxalic acid comes into contact with lime, it is instantly precipitated as crystals of oxalate of lime.

Another inorganic substance at times found in urinary calculi is silica (SiO_{2}). This contributes largely to giving stiffness to the stems of 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.