ACUTE CONGESTION OF THE KIDNEYS IN SOLIPEDS.
Definition. Causes: bacteria, toxins, irritant diuretics, musty oats or fodder, foul water, cantharides, turpentine, aqueous grasses, onions, moulting, cold, chills, injuries to loins, over-driving. Lesions: kidney enlarged, red, black, softened, capsule loose, cut surface drops blood, brown, softened necrosed areas, gorged capillaries of glomeruli and convoluted tubes, granular or fatty changes in epithelium, may be ruptures. Symptoms: sudden; weak tender loins, slow dragging straddling gait, accelerated pulse and breathing, anxious countenance, colics, sweating, urine from limpid to black, with red globules, and casts. Prompt recovery or nephritis. Diagnosis: from nephritis, hæmoglobinuria, laminitis, indigestion. Prevention: Treatment: bleeding, laxatives, diffusible stimulant diuretics, bromides, diluents, mucilaginous agents, fomentations, sinapisms, rectal injections, clothing, friction to the skin, restricted laxative diet.
Definition. Active congestion of the renal capillaries, especially of those of the glomeruli and convoluted tubes, with colicy pains, and free discharge of urine, in some cases bloodstained.
Causes. It may be determined by local irritation caused by the passage of the bacteria and toxins of infectious diseases such as influenza or contagious pneumonia. In the same way irritant diuretics, medicinal, alimentary and toxic, operate. Diuretic balls and condition powders given recklessly by stablemen and grooms, saltpeter, resin, oleo resins, turpentine, rue, savin, colchicum, squill, anemone nemorosa, adonis, cynanchum vincetoxicum and other species of ascelepias, hellebore, mercurialis annua and bryony are examples. The young shoots of the coniferous plants, fir, balsam fir, pine, white and yellow, and hemlock, are at times injurious.
In the same way, damp moldy oats or fodder produce renal congestion and excessive polyuria, also corrupt, stagnant water and that of marshes which often contains complex toxic products of fermentation. Water of ponds in which cantharides or potato beetles have been drowned, is dangerous. The cantharides, euphorbium or oil of turpentine applied too extensively to the skin as a counter-irritant, is another factor.
Even the rich aqueous grasses of spring succeeding to the dry winter diet, stimulate the kidneys, determining an active congestion with polyuria and in bad cases hæmaturia. In many such cases there are superadded the acrid diuretic plants already referred to. In Denmark where onions are grown on a large scale, the tops fed to animals have produced renal congestion.
There appears to be an extra susceptibility in spring when the winter coat is being shed, and at this time especially, but also independently of this and at other seasons, exposure to cold and the occurrence of chills tend to induce an attack. Exposure to cold storms of rain or sleet when perspiring or fatigued, standing tied out of doors in zero weather without a blanket, wading or swimming deep rivers in cold weather and while fatigued, standing wet and unblanketed in a cold stable when returned from work, exposure to draughts between open windows or doors, the continuous falling of cold rain, from a leaking roof, on the loins, the cold of a damp stable newly finished in brick or stone, the cold and damp of an undrained floor in a wet retentive soil, all have a tendency to drive the blood from the surface, to increase the tension of the blood in the heart and internal organs, to stimulate the kidneys to extraordinary secretory activity, and at the same time to temporarily debilitate the whole system and lessen the power of resistance and recuperation. The factor is especially potent when it involves the nervous interdependent sympathy between the chilled loins or abdomen and the kidneys. Sprains and other injuries of the loins have long been charged with producing renal congestion and inflammation, and even Trasbot, who doubts the reality of this, acknowledges that the already diseased kidneys are seriously injured in this way. Cadeac and Schmid record cases of actual rupture of the horses’ kidney from violent movement, and other cases of congestion and bloody urine have been traced to kicks on the loins, falls, sprains and the carrying of unduly heavy loads. The overexertion which produces albuminuria, casts and sanguineous transfusion in athletes has a similar effect on the overdriven race horse, trotter or draught horse.
Lesions. The congested kidney is enlarged, sometimes to two or three times its natural size, softened, and red, especially in the cortical portion which may be so dark as to appear cyanotic. The capsule is also the seat of ramified redness, and is very loosely adherent to the cortex. Beneath it may be considerable yellowish exudate especially abundant in the vicinity of the hilus. On section the cut surface is very bloody, the cortex literally dropping blood, though brownish spots may appear at intervals representing areas of necrosis, which under pressure break down into a pulpy debris. Microscopically the glomeruli appear hæmorrhagic, the capillary vessels being gorged to excess, while blood globules and even minute blood clots are found in the intervascular spaces. The epithelium covering the glomeruli and lining the convoluted tubes show granular or fatty changes, and granular matter is found outside the vessels.
The congestion is less in the medullary portion and even in the convoluted tubes and the tubes of Henle, though these may be the seat both of hyperæmia and exudation.
In case of very violent congestion, extensive sanguineous extravasation may occur, leading even to rupture of the capsule and the escape of blood into the perirenal adipose tissue or into the abdominal cavity. Cases of this kind in the soliped are recorded by Caroni, Cadeac, Moussu, Kitt, Zundel, Mollereau and Porcher. Averons describes in the Revue Veterinaire (1897) a case in which both kidneys were surrounded by an immense black clot, and weighed no less than 36 lbs. Leblanc records a similar case affecting the one kidney. The mass measured about 10 inches by 8.
Symptoms. These are liable to appear suddenly, often while the patient is at work, and are manifested by weakness in the loins, slow gait or sudden stopping, the hind limbs are held in abduction, and advanced with apparent stiffness and pain. There is much excitement and anxiety, the face is pinched and strained, the respiration accelerated, the pulse hard, tense and rapid, and the eyes or nose may be turned toward the flank or loins. There may be colicy pains, with uneasy movements of the tail and hind limbs, pawing, and even lying down and rolling. The visible mucosæ are strongly injected and in bad cases the skin may be drenched with sweat. There is at first little or no hyperthermia.
At first there may be no micturition but in an hour or more, urine may be discharged in excess, sometimes as much as 25 quarts, and of a low specific gravity (1001 to 1005). If there has been no blood extravasation it is usually clear and limpid but with extravasation it may be of all shades of pink or red to black. In the latter case the suffering is liable to be acute (Cadeac), and contrary to the condition in hæmoglobinuria, the urine contains blood globules and even tubular coagula representing the uriniferous tubes and entangling the blood cells. This is complicated by albuminuria.
Course. Duration. The congestion is short lived. It speedily undergoes resolution with the passage of normal, clear urine, and the recovery of appetite and spirit, or it becomes rapidly aggravated, with continuous suffering and colic, complete loss of appetite, dullness, constant decubitus, weakness, debility, small or imperceptible pulse, palpitations, darker color and perhaps complete suppression of urine, and stupor or other nervous disorder. Death may occur on the fourth to the sixth day. It may be delayed by a partial recovery followed by a relapse.
Diagnosis. Acute renal congestion is distinguished from nephritis by the suddenness of the onset, the absence of fever and the comparative absence of tenderness of the loins, and of tubular casts.
From hæmoglobinæmia it is distinguished by the absence of the conditions under which that affection appears:—the previous heavy work and full rich feeding, the day or more of complete rest on full ration, and the sudden exercise following. The hind parts in hæmoglobinæmia are benumbed, paretic, or paralytic and not unfrequently rigid and swollen, and the brownish or reddish urine contains hæmoglobin in amorphous particles, and not red blood globules and sanguineous tubular casts as in renal congestion.
From laminitis it is distinguished by the absence of high fever, by the absence of the advance of the fore feet resting on the heels, of the heat and tenderness of the feet, by the ability to bear the lifting of one fore foot, or the tap of a hammer on the toe, by the lack of improvement after the first few steps as is seen in laminitis, and by the absence of the strong pulsations in the digital arteries.
From indigestion it is distinguished by the absence of the history which leads up to that condition, of abdominal tympany, of rumbling, of impaction and of frequent attempts to defecate, and by the presence of the stiffness, straddling, and the blood globules and albumen in the urine of low density.
Prevention. This must be sought by the avoidance of all the factors of causation:—auto-intoxication in contagious diseases, excessive renal irritation from the injudicious use of diuretics, or the accidental ingestion of irritant or acrid diuretic plants or waters, or musty fodders, or the sudden change to the succulent, watery, first vegetation of spring, or of exposure to cold, wet, or damp, in all their forms, or of direct injury to the back or loins by blows, shocks, or violent exertions.
Treatment. Trasbot and Cadeac strongly recommend venesection, and at the very outset in specially acute cases the sudden lessening of the arterial and capillary tension, by this potent means, may furnish the opportunity for the capillaries of the glomeruli and tubes to regain their normal tone, and thus contribute to a speedy abortion of the affection. If resorted to at all it should be made in a full stream from the jugular, so as to secure the fullest and most prompt result with the least possible effusion of blood.
Much, however, must depend on the attendant conditions. In toxin poisoning following on an infectious fever, the already existing debility will sufficiently forbid a resort to the lancet, and we must seek elimination by the bowels, the skin or even the kidneys. Antiseptics, too, are in order if there appears any ground for suspicion of the action of infecting agents. Some cases will recover promptly under diffusible, stimulant diuretics such as spirits of nitrous ether, which by stimulating the circulation in other organs and especially the skin, appears to relieve the kidney and solicit normal secretion. But most veterinarians dread the stimulus and irritation and prefer small doses of refrigerant diuretics: bicarbonate of soda 4 drs., saltpeter 2 drs. or the tartrates, citrates or acetates of the alkaline bases. In case of irritation by acrid diuretics, but especially by cantharides, camphor 2 drs., has been found to be particularly soothing, and next to this, bromide of camphor or bromide of potassium 1 to 2 drs. may be resorted to. Zundel prescribes acidulated camphorated drinks. The free use of mucilaginous drinks, such as boiled flax seed; and the persistent application of fomentations or wet compresses to the loins are of equal value in soothing irritation. Sinapisms may advantageously follow the local emollients.
Laxatives act with less promptitude than diuretics, but on the whole constitute a safer treatment, since they secure elimination and derivation without risk of irritation to the kidneys. The oils: castor 1 to 2 pints, linseed 2 pints, or olive 2 pints, are especially to be recommended in this respect, but l’Homme advises manna, and calomel may also be used as a substitute. Injections of warm water are valuable in unloading the rectum and colon, soothing the kidneys and soliciting peristalsis.
A restricted amylaceous diet is essential, and a warm stall or abundant clothing. Grooming or active rubbing of the skin tends to active derivation and often materially relieves. The case should not be abandoned until a day or two after the urine has returned to the normal, and for some time special care should be taken of the diet, stabling and work.