ADDENDA TO THE DISEASES OF THE KIDNEYS. 



389 



Etiology. The causes of retention of the urine are the fol- 

 lowing : 



1. The prevention of micturition by foreign bodies in the bladder 

 and urethra : ureteral and vesical calculi, sediments in the S-curved 

 penis in the ox and ram, a fragment of broken catheter ; bloody or 

 fibrinous clots, diphtheric or croupous membranes detached from 

 the vesical mucous membranes, polypous tumors producing occlu- 

 sion of the urethral canal, etc. ; foreign bodies introduced inten- 

 tionally into this duct : straws, broom sprig, etc. 



2. Compression and obturation of the urethra or of the neck of 

 the bladder by neoformations developed in the neighboring organs 

 (prostate, uterus, ovaries, the bladder itself — leiomyoma, also by 

 the accumulation of excrements in the rectum, displacements of 

 the uterus, gestation ; also by contractions of the urethra, by con- 

 strictions, inflammation, or tumefaction of the walls of the canal, 

 by a fracture of the penis or of the penic bone, paraphimosis 

 (strangling of the glans penis by a tumefied prepuce) or phimosis 

 (abnormal narrowing or displacement of the opening of the 

 prepuce). 



3. Paresis or paralysis of the bladder in consequence of croupous, 

 diphtheric, or phlegmonous cystitis, pericystitis, affections of the 

 spinal cord (traumatisms, spinal meningitis, apoplexy, etc.); a 

 general weakness ; infrequent defecation (in horses suffering from a 

 cerebral affection, or in those which have made a prolonged journey) ; 

 a reflex paralysis of the muscular wall of the bladder, occurring 

 either during colics or in the course of rheumatismal hemoglobin- 

 emia of the horse, or of certain general serious morbid states (vitu- 

 lary fever, etc.). 



4. Tetanic contraction of the vesical sphincter caused by the 

 action of cold or by cystitis, by foreign bodies in the bladder ; 

 reflex spasms in colics, tetanus, etc. 



The enumerated causes in the first two groups just established 

 produce mechanical retention of the urine, and the others dynamic 

 retention. This latter alone enters into the domain of internal 

 medicine. 



The urinary calculi, which are especially important from a sur- 

 gical standpoint, have a triple origin : often they are formed by the 

 precipitation of urinary salts around foreign bodies in this liquid 

 (clots, spermatozoa, etc.) ; at other times they are due to the excess 

 of such salts in the urine — a phenomenon due to the influence of a 



