Causes: general, traumatic, metastatic, infective, wounds, shocks,
strains, blows, falls, crowding, heavy loads, calculi, infective
embolism. Lesions: miliary or large abscesses, diffuse suppuration,
softening, disintegration, fistula. Symptoms: obscure, nephritic
symptoms following distant abscess, chill, hyperthermia, general
symptoms of nephritis, pus in urine, anæmia, emaciation. Treatment: to
external wound, antiseptics, evacuate abscess, extirpate kidney with
pyonephrosis, in dog or pig, calcium sulphide, sulphites, copiaba.
_Causes._ Aside from the main causes of nephritis, the suppurative form
may be determined by traumatic or metastatic infective conditions. Under
_traumatic_ factors may be named punctured or gunshot wounds, shocks and
strains connected with falls, blows, crowding, compression, too heavy
weights on the back (pack, rider, two wheeled cart loaded too heavily
forward and going down hill), and finally calculi in the uriniferous
tubules. Under _metastatic_ factors come all infections, pyæmia,
omphalitis, any suppurative affection of the lungs, (abscess, pneumonia,
broncho-pneumonia), pharyngitis, etc. Embolic renal abscess may start
from endocarditis, arteritis, or pulmonary phlebitis.
_Lesions._ There may be a circumscribed renal abscess like a good large
orange, or many small gray spots like millet seeds, peas or hazel nuts,
having purulent centres and containing pus cocci or bacilli. In other
cases a diffuse inflammation suppurates throughout till the whole gland
becomes a pulpy mass of pus, blood and broken down kidney tissue
(pyonephrosis). In traumatic cases the pus centres around the wound or
injury, perhaps invading adjacent parts, and even communicating through
the skin externally along the line of the original wound. The pus may
burrow in different directions in the cortex or under the capsule with
abscess at intervals (perinephritis), or along the vessels to the
medullary structure.
_Symptoms._ These are often obscure. The sudden appearance of kidney
disease in the course of a suppurative affection elsewhere, the
extension being ushered in by a chill or rigor or attended by a
succession of these, and the course marked by a variable hyperthermia is
very suggestive. Stiffness and weakness of the hind parts and tenderness
of the loins are significant; also, in carnivora and omnivora, nausea
and vomiting. When the kidney can be felt by the hand in the rectum or
in the small animals, through the flaccid abdominal walls, the manifest
enlargement, the tenderness, and in some cases even fluctuation will
assist in diagnosis. In such cases, puncture by a large hypodermic
needle, or a small trochar may betray the presence of pus and complete
the diagnosis. If the pus escapes into the pelvis of the kidney it may
be recognized in the urine. The case is very liable to become chronic,
and is then marked by anæmia and emaciation.
_Treatment._ When an external wound exists it must be treated,
antiseptically, with boric acid, potassium permanganate, or other
antiseptic lotion. If a single large abscess exists, puncture evacuation
through needle or trochar, and washing out with an antiseptic solution
is the obvious resort. Any foreign body must of course be removed. If
the suppuration is diffused through the whole mass of softened kidney,
the resort of extirpation may be considered. This is always dangerous as
provocative of infectious peritonitis, but it is less so in dogs and
swine than in other animals owing to their natural antagonism to pus
microbes. The operation should be attempted extraperitoneally, the
incision being made beneath the anterior lumbar transverse processes and
carried inward through the sublumbar connective tissue. The renal artery
will require ligature with antiseptic catgut and all manipulations
should be aseptic or antiseptic. Even if successful, this operation
leaves the subject in a dangerous state, as in case of kidney disease at
any future time, there is no second kidney to compensate for the
temporary loss of function and uræmic poisoning is to be dreaded.
Apart from surgical measures the general treatment would be largely the
same as for acute infectious nephritis. As antiseptics calcium sulphide,
the different sulphites, copiaba, etc., will be indicated.