204 DISEASES OF THE KIDNEYS 



pus and its walls ulcerated, necrosis of the papilla, diffuse 

 purulent nephritis with abscesses in the cortex and chronic 

 interstitial nephritis. 



Symptoms. — Most cases of pyelonephritis occur in cows fol- 

 lowing parturition. This is especially true when injuries have 

 occurred in the uterus or vagina or where retention of the 

 afterbirth has followed. It may, however, originate independ- 

 ent of parturition. In sucklings infection through the navel 

 can occur and in male animals it has resulted from primary 

 abscesses. There is also a probability that the infection may 

 be introduced via the digestive tract. The clinical symptoms 

 are usually rather indefinite. In a cow which has calved with 

 difficulty or suffered from retention of the placenta the con- 

 dition of the animal grows bad, the appetite and rumination 

 suppressed, the patient losing flesh, showing fever, colicky 

 pains, irregular gait, frequent urination and sometimes 

 strangury. Pressure over the sacrum causes pain and the 

 tail and buttocks are soiled with pus which flows from the 

 vagina. The urine in rare instances remains clear, but is 

 usually cloudy. On rectal examination the bladder is found 

 partially filled, the ureters dilated and sometimes the kidneys 

 enlarged, sensitive and fluctuating. The chemical analysis of 

 the urine shows albumin and free ammonia. Under the 

 microscope pus cells, blood, crystals of triple phosphates, 

 and renal epithelial cells are found. With the Gram stain 

 large numbers of bacteria — the corynebacilli — are found 

 generally arranged in clumps. As cystitis is a common com- 

 plication, bladder epithelium will also be found in the urine.' 



Diagnosis. — Diagnosis depends upon the examination of 

 the urine and the determination of the corynebacillus which 

 is usually present. The rectal findings, tbe fact that the urine 

 contains pus, and the failing of the patient after parturition, 

 point to pyelonephritis in cows. 



Prognosis. — Prognosis is bad, therefore it is advisable to 

 make the diagnosis as early as possible so that the animal may 

 be slaughtered. 



Calculous Pyelonephritis (Kidney Stones). — Defini- 

 tion. — This is an inflammation of the pelvis of the kidney due 

 to the presence of renal stones (nephrolithiasis). The stones 



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