182 DISEASES OF THE URIXARY AND SEXUAL APPARATUS 



Acute Inflammation of the Kidneys. 



(Acute Nephritis; Nephritis Acuta.) 



Etiology. — The most common causes of this condition are infec- 

 tious diseases and poisons. By this is meant the effect produced l)y 

 the absorption of infectious noxious agents, such as the various septic 

 cUseases, or certain irritants that have originated in the body and are 

 passed into the kithieys and cause great irritation while they are passing 

 through these organs, and also certain micro-organisms that reach the 

 blood and become located in the capillaries of the kidneys. Certain 

 chemical substances, such as phosphorus, arsenic, lead, mercury, copper, 

 cantharides, turpentine, colchicum, male fern extract, strong spices, 

 carbolic and tar acids, naphthol, and chrysarobin, that are absorbed or 

 taken into the stomach pass through the kidneys and cause great inita- 

 tion. Some of these chemical substances are absorbed by the skin 

 from various ointments that are applied in mange, such as carbolic acid, 

 mercury, cantharides, balsam of peru, storax, etc. 



Acute nephritis may also originate from an extension of inflamma- 

 tion from neighboring organs, and also from traumatic influences, such 

 as blows, shocks, etc., in the regions of the kidneys. There is a condition 

 called rheumatic inflammation of the kidneys that is supposed to origi- 

 nate from cold. This occurs generally in young dogs during severely 

 cold weather. 



Pathological Anatomy. — The alterations in the structure of the 

 kidney depend on the intensity of the irritation, and the alterations 

 are more or less distinctly marked. In slight cases the epithelium seems 

 to be the only part affected, the connective tissue and the blood vessels 

 show no pathological alteration other than a reddish-gray coloration 

 of the covering, or sometimes a yellowish coloration (parenchymatous 

 degeneration). AMien the irritation is great, there is true parenchyma- 

 tous inflammation of the kidneys. The epithelium and the inter- 

 mediate tissue become affected, as do the blood vessels, and all the 

 exudation processes which accompany acute nephritis follow. The 

 anatomical alterations that are fovmd are as follows: The epi- 

 thelium has undergone extensive desquamation, as in parenchyma- 

 tous degeneration, Ijut more acute in its type. The capsules of the glom- 

 eruli and the small urinary canals are altered, and the connective tissue 

 is filled with a liquid infiltration forming numerous coagulated masses 

 containing large numbers of Icukoc^'tes rich in hydrogen and the urinary 

 canaliculi are filled with hyaline and epithelial cylinders. The vessels 

 are enlarged (hypenemic) and partially compressed by the surrounding 



