PURULENT NEPHRITIS.
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.