Part 41

4th. Chronic diffuse (desquamation, interstitial) nephritis.

5th. Suppurative nephritis and pyelo-nephritis, infection may be from injury.

6th. Perinephritis: infection of connective tissue with adjacent disease.

In domestic animals the following distinctions have been made:

1st. Acute nephritis.

2d. Chronic nephritis.

3d. Purulent nephritis and pyelo-nephritis.

4th. Perinephritis.

ACUTE NEPHRITIS. ACUTE BRIGHT’S DISEASE.

Animals affected. Causes: hyperæmia, traumas, cold, chill, fever, bacteria, toxins, overfeeding, nitrogenous food, raw potatoes, xanthin products, acrid diuretics, diuretic insects, suppression of micturition, skin lesions, burns, embolism, calculus. Symptoms: colic, trembling, rigor, arched, stiff, tender loins, stiffness in quarters, drags hind legs, urination frequent, movements of penis and testicle, costiveness, grinding teeth, anorexia, vomiting (in dogs, cats and pigs), fever, dropsies, uræmic convulsions, urine scanty, high colored, red or bloody, thin, cloudy or turbid, albuminous, purulent, oxalates, urates, hippurates, hæmatoidin, epithelium, mucus, casts. Prognosis: resolution in three days, or uræmia, suppuration, degenerations. Lesions: kidney enlarged, softened, friable, red, yellow, black, purulent, glomerulitis, tubular nephritis, interstitial nephritis. Treatment: rest, warm building, warm clothing, green or sloppy, amylaceous food, bleeding, cupping, skin friction, fomentations, warm bath, hot air bath, sinapisms, anodynes, laxatives, diaphoretics, heart tonics, alkaline diuretics, paracentesis, bitters, iron, phosphates, hydrogen peroxide, cubebs, etc.

Genera affected. This has been seen in horse, ox, dog, sheep and pig.

Causes. It is ascribed to the most varied causes, such as: hyperæmia, blows and injuries on the back and loins, sprains of the loins, abrupt wheeling when in galop, exposure to cold winds, and storms, especially when perspiring and fatigued, sudden suppression of perspiration, extreme terror, bacterial infection and infection by toxins (in septicæmia, pyæmia, influenza, contagious pneumonia, uterine sepsis, omphalitis, infectious angina (Friedberger), bronchitis (Siedamgrotzky), glanders, tuberculosis). Among dietary causes are named: a rich nitrogenous food (grains, beans, peas, vetches, cotton seed, clover), raw potatoes in excess, cotton seed meal, agents that increase the nitrogenous and xanthin bodies in the urine.

Dr. Alfred C. Croftan, in his experiments with xanthin bodies on rabbits, found that xanthin and hypoxanthin produced great increase of arterial pressure, atheromatous changes in the vessel walls consisting in thickening of the intima, with small celled infiltration and necrotic changes in different areas of the vessel walls. This in the kidney produces the primary interstitial form of nephritis known as gouty kidney and associated with retention of uric acid and other xanthin bodies. The accompanying cardiac hypertrophy, so common with such kidneys, he attributes to the increased intravascular pressure.

Irritant vegetables that are resinous or diuretic, and irritant diuretic insects are incriminated (cantharides, caterpillars in grass, or on plants, etc., lice on cabbages particularly,—Cruzel, Neubert). Irritant drugs that are eliminated by the kidneys have been equally charged (tar, carbolic acid, iodoform, chlorate of potash, nitrate of potash, phosphorus, arsenic, lead, mercury). Compulsory suppression of micturition is undoubtedly injurious in house dogs shut up, mares kept long in harness, or horse on railway car, above all if this follows a diuretic or drinking abundantly. In such cases it is altogether probable that bacteria already exist in the blood or kidneys and take occasion to attack the tissues weakened by the overdistension or other inimical cause. This is all the more probable seeing that the kidneys are a favorite channel for the elimination of bacteria present in the system. It should be noted that nephritis is liable to supervene on extensive skin burns, chronic dermatitis and other skin diseases. Some cases are traceable to embolism, the clots coming from the lungs, heart or arteries, in others the irritation is due to calculi in the renal pelvis or tubules, and their attendant bacteria. These are especially common in cattle that are winter fed on dry food. Again, the infection may have travelled forward through the ureters from a pre-existing infective cystitis.

Symptoms. There may be obscure or intense colic; trembling or rigor may occur, yet is often omitted or unobserved; the loins are arched; the hind feet are advanced under the belly, or there is frequent shifting of the weight from one foot to the other; the walk shows stiffness of the back and hind limbs which appear to straddle or drag behind; urination is frequent in small amount, or there are frequent ineffectual attempts to urinate; the patient is indisposed to lie down, and if he does so it is carefully, with difficulty and groaning; the testicles are drawn up and dropped alternately, the penis is often protruded from and retracted within its sheath, the loins are sensitive to pinching, percussion, or electric current; when mounted the animal drops under the weight; he carries the head low and refuses to go fast. In bad cases there is constipation, grinding of teeth, anorexia, and in dogs, vomiting. Temperature may be normal or there may be considerable fever. Dogs may lie curled up, with occasional tremors. Dropsical effusions are frequent in the form of anasarca under the chest or abdomen, or beneath the lower jaw, or as stocking of the limbs, or the effusion may occur into an internal serous cavity. Convulsions may occur from brain poisoning by urea or other retained urinary product.

In the slighter forms the severe symptoms may be absent, and the condition of the urine must be investigated as affording the most constant and characteristic phenomena.

The urine is usually scanty, high colored, of a high specific gravity and is passed often with pain and groaning. At the outset of an acute attack it may be bloody; later it may be only cloudy or turbid from the excess of epithelial and pus cells, leucocytes, salts and albumen. Early in the disease the casts may contain red blood cells, and renal epithelium, later leucocytes, nuclei, granules, pus cells, crystals and other matters. Albumen is usually abundant as demonstrated by boiling and nitric acid.

Soda carbonate crystals, rhomboid, rosette-shaped or spherical and effervescing with acetic acid, abundant in normal herbivorous urine may be greatly reduced or absent in nephritis.

=Soda oxalate crystals=, tetrahedral and insoluble in acetic acid, and normal in herbivora and carnivora, are increased if the urine is acid as in severe nephritis, but also in rheumatism, tetanus, septicæmia, angina, heaves, and other affections with defective æration of the blood.

=Ammonio-magnesian phosphate crystals=, rhomboid but insoluble in acetic acid, are found in alkaline (ammoniacal) or neutral urine, and appear to be often due to intestinal fermentations.

Cystine crystals, flat hexagonal plates, precipitated in healthy urine, but dissolved by ammonia are absent in retained and fermented specimens.

=Uric acid crystals=, rhomboids and plaques, brick red, and normal in the urine of carnivora and flesh-fed omnivora, may be present in herbivora not only in acute nephritis, but in other extensive inflammations attended with anorexia and the consumption of the animal tissues.

=Hippuric acid crystals=, right rhombic prisms and their derivatives, and insoluble in hydrochloric acid or ether, are greatly increased in all febrile diseases in herbivora, nephritis included.

=Hæmatoidin crystals=, fine needles or bundles of the same, yellowish red, are found in nephritis, hæmaturia, heaves, etc.

=Epithelium, if columnar=, points to disease of the kidney tubes, though very similar cells are derived from the urethra in both male and female. Squamous epithelium points to the cystic mucosa and is not increased in nephritis.

=Mucus= in cylindroid form may point to nephritic congestion or inflammation, but this may be present in health, and may show in irregular masses derived from the renal pelvis or the bladder. Mucous casts are always extremely elastic and mobile, and lack the even clear cut margins of the casts of nephritis. They are much more common in horses urine than in that of other animals.

=Tube casts= are especially indicative of nephritis and exudation into the uriniferous tubes. They are much firmer than the mucous cylinders and have smoother and more even margins. If relatively thick and straight they probably come from the straight tubes; if sinuous or twisted, from the convoluted tubes. With a similar basis substance they often enclose different solid bodies and have been named accordingly:—=epithelial casts= when containing cylindroid, or polyhedral cells may be unhesitatingly referred to the uriniferous tubules:—=granular casts= in which the homogeneous cast is impregnated with granular cells and free granules of proteid, fatty, or mineral matter, point directly to inflammation affecting the uriniferous tubules and their epithelial lining:—=blood casts= enclosing red blood globules imply hemorrhage, or congestion or inflammation of the tubules, with blood extravasation or diapedesis:—=casts containing leucocytes and pus cells bespeak= suppurative inflammation of the tubules:—=calcareous casts= entangle numerous crystals and granules, mainly of lime carbonate, and effervesce with acetic acid:—=hyaline casts= are homogeneous, clear, so transparent that it is sometimes necessary to stain them with iodine or aniline to make them distinct; they are found in nephritis and especially in the chronic forms:—=colloid casts= or =waxy casts=, or =amyloid casts= may designate a class of firmer cylinders, clear, homogeneous and refractive, and often bearing fatty or blood globules, crystals or fungi. They may have a yellow color, or they may give the amyloid mahogany reaction with the iodo-potassic iodide solution (even in the absence of amyloid degeneration of the kidney; Jaksch).

Progress. Acute nephritis may advance for three days or more and then terminate in resolution, or go on to complete anuria with coma, to suppuration, gangrene or chronic nephritis.