PURULENT NEPHRITIS 397 



infection spreads to the organ via the bladder, ureters, and 

 pelvis of the kidney. 



In small animals 'Subjection to extremes in temperature 

 has been mentioned as an indirect factor in bringing about 

 the condition. 



Pathology.— We recognize two forms of purulent nephritis 

 on postmortem: 



Diffuse Purulent Nephritis {Nephritis purulenta punctata, 

 diffusa). —In this form the kidneys are enlarged; numerous 

 small white spots or yellowish dots are present which are sur- 

 rounded by a reddish zone. On close examination the puru- 

 lent masses may be easily removed. These foci of infection 

 may be found quite generally distributed in one or both 

 kidneys. 



Microscopically there is found a large number of pus cells 

 in the foci of infection, cellular infiltration with large numbers 

 of bacteria present in the tissue surrounding them. The 

 epithelial cells show fatty degeneration, the glomeruli 

 surrounded by pus, and the tubules partially filled with 

 leukocytes, red blood cells, and casts. 



Nephritis Apostematosa (Renal abscess).— Vie find in this 

 form abscesses of varying size, which may be a single abscess 

 formed from an embolus, or the kidney tissue break down to 

 form a very large abscess (pyonephrosis). The connective 

 tissue increases around the abscess forming a thick wall. 



Symptoms.— Clinically it is quite difficult to recognize this 

 condition. In cases which originate by metastasis we will 

 observe the symptoms of the primary condition, such as 

 pyemia, endometritis, etc. 



Should the disorder develop rapidly, there will be found 

 practically the same symptoms as in acute diffuse nephritis. 

 (See Acute Nephritis.) 



In dogs the patient becomes very stiff, refuses to move, 

 shows pain on palpation over the region of the kidneys; in 

 some cases a distinct enlargement on one or both sides high 

 in the lumbar region can be determined. In examining such 

 cases the animal should lie placed in a standing position, 

 both hands used, one on either side of the animal, and the 



