204 CANINE MEDICINE AND SURGERY 



and pleura do not coincide, thus averting the en- 

 trance of air through the wound. After withdrawal 

 of the cannula the wound is swabbed dry and sealed 

 with iodized collodion. 



Paracentesis Abdominis 



PUNCTURE of the abdominal cavity by means of 

 a trocar and cannula is necessary for the re- 

 moval of the ascitic transudate in cases of abdomi- 

 nal ascites or the exudate of chronic peritonitis. 



The operation is harmless provided surgical meth- 

 ods are observed, and may be repeated with perfect 

 safety as often as circumstances require. 



The patient must be in the standing position, 

 held securely by an assistant and muzzled. For 

 instruments use a razor, trocar and cannula, and 

 probe, and for dressings have ready iqdin, swabs, 

 and iodized collodion. 



Technic. — Shave and disinfect an area about two 

 inches square just posterior to the umbilicus. At a 

 point one inch behind the umbilicus introduce the 

 sterilized trocar and cannula obliquely through the 

 skin for one half an inch, then direct the trocar 

 straight upward and press, until the loss of resistance 

 indicates that the abdominal wall has been pene- 

 trated. Withdraw the trocar and allow the fluid to 

 escape through the cannula. Should the flow cease, 

 the cannula is probably blocked by the omentum or 

 by a clot, and the probe should be inserted and the 

 obstruction gently pushed away. In withdrawing the 

 cannula the fingers should press against the skin as 

 in paracentesis thoracis, and for the same reason. 

 After withdrawal, the wound should be swabbed 

 with iodin and sealed with the iodized collodion. 



Paracentesis Vesicae 



Puncture of the bladder is rendered necessary 

 when that organ is dangerously distended with 



