Friday, May 3, 2013

Three things I learned: Peritonitis in cats and dogs

Dorsoventral radiograph of a shih tzu with a radioopaque gastric foreign body (in this case, a beer bottle top). This was an incidental finding in a dog which had been hit by a car (hence the thoracic imaging!). Foreign bodies can cause GIT obstruction, perforation and peritonitis.

The University of Sydney Veterinary Centre hosted a continuing education evening on the topic of peritonitis in the dog and cat. The presentations by Drs Alastair Franklin, Mark Newman, Heide Kloeppel and Chris Tan were fantastic.

So what did I learn?

·         The peritoneum is equivalent to 150 per cent of the body surface area, and the hypovolaemia and hypoproteinaemia that occur with peritonitis are similar to losses which occur with third degree burns.

·         Secondary peritonitis is the most common form, with 50 to 75 per cent of cases occurring due to loss of GIT integrity (and around 15 % of GIT resection and anastomoses break down – even those performed in referral facilities).

·         Aseptic peritonitis can be caused by endogenous chemicals (bile and urine – which I knew) but also exogenous chemicals (iodine and saline – yet we are required to flush with the latter! It does raise the question, in what circumstances is saline likely to cause peritonitis? I would expect it would be failure to suction all lavage fluid prior to wound closure, which might turn it into a medium for bacteria?)

·         It’s simple, but worth remembering: take rads before you perform your abdominocentesis, as even with careful technique you can introduce gas into the abdomen which complicates radiograph interpretation.

 The talk covered everything from abdominocentesis fluid analysis to anaesthetic considerations and ex-lap technique, emphasising the need for a multidisciplinary approach to a challenging problem.