250 
TAPPING THE PERICARDIUM IN THE DOG. 
intercostal space three or four fingers’ breadth above the lower margin of 
the thorax. As soon as its end has fairly entered the thoracic wall the 
tap connected with the aspirator is opened and the needle very gently 
pushed forward until liquid appears in the glass index of the rubber tube. 
Operating in this way the needle need only just enter the pericardium, 
and with a short point, injury of the heart (which is always pushed 
upwards and shortened in its vertical axis) need not be feared. 
Furthermore, by using a small needle, fluid is very slowly withdrawn 
and danger of syncope prevented. In the absence of an aspirator, 
puncture may be effected with a fine trochar. The injection of warm 
1 per cent, boric acid solution or normal salt solution has been suggested 
after withdrawal of the fluid contents of the sac, but is difficult to 
perform and of doubtful utility. After operation the wound is closed 
by painting with collodion, and the parts covered with a cotton-wool 
dressing and a bandage. 
During the following days the patient is fed on milk, milk preparations, 
meat juice, or fragments of raw meat. When appetite returns, more 
substantial food and tonics may be given. 
When pericarditis is complicated with ascites it is not always necessary 
to tap the abdomen. Once the pericardium is relieved, the peritoneal 
exudate tends naturally to become absorbed. 
