2i6 Surgical Diseases and Surgery of the Dog 



with foodstuffs. The administration of oxamethane and oxaminic 

 acid produced no effect, but oxamide did. Oxamide is an odor- 

 less white powder, obtained by heating oxalate of ammonium. It 

 was given in doses of four to six grams for six weeks with as 

 little water as possible. Ebstein's explanation of its effect was as 

 follows : the oxamide was dissolved in the digestive tract, absorbed, 

 and eliminated by the kidneys, where it induced organic altera- 

 tions, notably in the glandular epithelium. The latter underwent 

 necrosis and thus was produced the initial albuminoid nucleus in- 

 dispensable to the formation of all calculi. Tuffier repeated these 

 experiments and also examined for the presence of microorganisms 

 on the surface, and in the depths of the calculi with negative result. 

 This upset the bacterial theory of formation in favor of the physico- 

 chemical. The artificial calculi were extracted and the animals 

 subsequently restored to health. 



It has been known for a long time that foreign bodies in the 

 bladder are very apt to become encrusted with urinary salts. In 

 the seventeenth century Anton Nuck introduced a piece of wood 

 within the bladder, and found it had become covered with in- 

 crustations at the end of several weeks. Tuffier in recent years 

 observed that while a foreign body with perfectly smooth surface 

 did not favor the formation of deposits, one with a rough surface 

 did, particularly if it were septic. On a piece of rough aseptic 

 silk he found deposits, but on smooth catgut there were none. 

 Moreover, catgut was absorbed in two weeks' time. This fact 

 would seem to have an important bearing on the selection of sutures 

 for surgical purposes, but it must be mentioned that Maksimow 

 found that catgut used for cystorraphy experiments when it pene- 

 trated the mucosa, became the seat of deposit of urinary salts. 

 Znamensky found incrustations on carbolized silk sutures which had 

 penetrated the mucosa, sixteen days after performing a resection 

 experiment. On the other hand, Thomson failed to find 

 any seven weeks afterwards, in an instance where two sutures had 

 penetrated. In certain ureteral-suturing experiments conducted by 

 myself there were no signs of incrustation after periods ranging 

 from three to seven weeks. 



Calculi of uric acid or urates (ammonium urate) are usually 

 small, hard, smooth, and yellow, brown, or reddish. They are 

 the most common to be met with, and originate as a result of uric 



