330 SALIVARY CALCULI AND CONCRETIONS. 



(4.) SALIVARY CALCULI AND CONCRETIONS. 



Calculus deposits are sometimes encountered in the ducts of the 

 salivary glands, especially of the parotid, in horses and cattle, and 

 may attain the size of a goose's egg. They are commonest in the 

 horse, ass, ox, and sheep. Schumann discovered one in a horse 

 which weighed over 7 ounces, and Stockfleth a similar one of 

 12| ounces, but calculi have been found weighing 75 ounces. Their 

 form is oval, colour greyish-yellow, surface usually smooth, though 

 where several are together they show facets. In herbivora, according 

 to Lasaigne, they consist of 80 to 90 per cent, carbonate of calcium, 

 3 per cent, phosphate of calcium, and 9 to 10 per cent, of organic 

 substances, composed chiefly of salivary corpuscles and bacteria. In 

 men and carnivora, phosphate of calcium is an important ingredient. 

 Foreign bodies entering the salivary duct, or injuries of the mucous 

 membrane, are the usual immediate causes. The cut surface of such 

 concretions often presents a stratified appearance, and a central 

 nucleus of oat-grain, awn, glume, or straw. 



Symptoms. The concretion is only remarked after it has attained 

 a certain size. It appears as a hard, sharply defined, slightly movable 

 swelling, generally lying on the outer surface of the under jaw, 

 slightly below the buccal opening of Stenson's duct, but some- 

 times over the posterior border of the under jaw. The salivary 

 duct is usually distended behind the swelling, and when the flow 

 of saliva is entirely shut off the gland is enlarged. Inflammation 

 is seldom present, but may appear and lead to abscess formation. 



Treatment consists in operative removal. Small concretions may 

 perhaps be forced through the duct, which will necessarily be some- 

 what fissured ; the larger require an incision to be made in the duct. 

 In this case a transverse cut is preferable to a longitudinal one, on 

 account of its healing more easily, and not so frequently leading to 

 salivary fistula. Recovery is hastened by observing strict antiseptic 

 precautions before and during operation, carefully suturing the 

 wound, and withdrawing food for one to two days. Bayer removed 

 a concretion from the duct through a longitudinal incision, and after 

 closing the wound with Lembert's suture, effected healing by first 

 intention. In some cases, where the calculus is lodged very near 

 the opening of the duct, it may be removed by incision from the 

 buccal cavity. Such cases are rare, but the fact is worth remem- 

 bering, as this method avoids the occurrence of a salivary fistula. 



