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.