R1£TRuc;kkssive tissuk cii.\.\(;l:s. 



233 



artenohths, and phleboliths are usually compused uf the carbon- 

 ates and phosphates of calcium and magnesium. Lacteal calculi 

 are composed chiefly of phosphates. 

 Varieties. 



Urinary Calculi are of frequent occurrence and may be con- 

 veniently classiiied according to the location in which they 

 occur. 



1. Renal tubular calculi are most common in dogs and cats, 

 but may occur in horses, cattle and hogs. After formation they 

 frequently pass into the pelvis of the kidney and the urine mav 

 wash them down through the ureter into the bladder and some- 



Fi&. 122. — Photograph of a 7 ounce Cystic Calculus successfully removed from the 



bladder of a jack. 



times on out of the anin:al bod_y. Thev may obstruct the tubule 

 causing retention of urine with distension of the tubule and fre- 

 quently cyst formation. 



3. Renal pelvic calculi are not rare, the pelvis of the kidnejf 

 sometimes being completelv filled with a calculus. This variety 

 has been observed in the hog, drig, cat, horse, and sheep, the 

 frequency in the difl:'erent animals being in the order named. 

 A 7-gram (H o^-) renal pelvic calculus was obtained in lOOG 

 from a horse used for dissection jnirposes at the Ivansas City 

 \"eterinary College. G. H. Woolridge, of Dublin, describes a 

 case of calculus formation in the renal pelvis of a horse (Veter- 

 inary Journal for June, 1907) in which the entire kidney was 

 practically replaced by the calculus. The results of calculi in 

 the renal pelvis depend upon their extent. Complete obstruc- 

 tion necessarily results in the retention of urine followed either 

 by its resorption (producing uremia) or its accumulation (form- 



