126 CANINE AND FELINE SURGERY 



cases, being applied w-hen the mouth is held open. Sharp 

 pieces of bone frequentK' get wedged across the mouth, each 

 end becoming inserted bet\\'een the molars, and occasional})' 

 the hollow shaft of a long bone becomes fixed longitudinally 

 on the molars, causing the mouth to be propped open (see 

 Fig. 94). 



The illustration shown in Fig". 95 is that of half the pelvis of a sheep. 

 A fox-terrier had, in endeavouring to crack it, forced his lower jaw 

 through the obturator foramen, and it had become so tightly wedged that 

 a piece had to be sawn out before the animal could be released. 



When removing a needle, care must always be taken to see 

 in which direction the point has entered, as neglect of this 

 precaution may lead to the breaking of the needle and 

 unnecessary laceration of the mucous membrane. 



Ranula. 



This term is applied to a large bleb-like swelling which 

 appears at the lateral or under surface of the tongue, usually 

 near the frenum. It ma}- come \\ithin a few daj's, or maj' 

 take three or four days to become of such a size that atten- 

 tion is drawn to it. It is painful, and causes the patient 

 considerable incon^'e^ience, producing free salivation. In 

 some cases it becomes of such size that the mouth is propped 

 open. It is due to cystic degeneration, or perhaps to blocking, 

 and consequent enlargement, of one of the mucous glands of 

 the mouth. The contents of the swelling are a thick, glairy 

 mucous fluid. 



Operation. — B}' the aid of a speculum the mouth is fixed 

 open, the tongue being dra\\n to one side or so arranged as 

 to place the ranula in the most suitable situation for removal. 

 The swollen sac is then punctured with a scalpel or sharp 

 pair of scissors, the whole of the \\all being dissected away 

 as closeh' as possible. Great care must be exercised about 



