An analysis of pH, pO2 and pCO2 in the peritoneal fluid of dogs with ascites of various etiologies.

The aim of the study was to assess pH, pO2 and pCO2 in peritoneal fluid. The study was conducted on a group of 22 dogs with symptoms of ascites. Group 1 consisted of 4 dogs with adenocarcinoma, group 2--of 6 dogs with glomerulonephritis, group 3 of 8 dogs with hepatic cirrhosis and group 4 of 4 dogs with bacterial peritonitis. An abdominal cavity puncture was performed in all dogs and the fluid was drawn into a heparinized syringe in order to assess pH, pO2 and pCO2 . The analysis of pH in the peritoneal fluid revealed statistically significant differences between group 4 and groups 1 (p=0.01), 2 (p=0.01), and 3 (p=0.01). The lowest pH value compared to the other studied groups was recorded in group 4. In group 4, the pO2 was the lowest compared to the other groups (group 1 p=0.01, group 2 p=0.01, group 3 p=0.01). The value of pCO2 was the highest in group 4 compared to groups 1, 2, and 3. The study found statistically significant differences in pH, pCO2 and pCO2 between group 4 (the group of dogs with bacterial peritonitis) and the other groups of dogs. This was probably linked to the pathogenesis of peritonitis. As a result of an inflammatory reaction within the peritoneal cavity, there is an increase in fibrin accumulations leading to a decreased oxygen supply causing the oxidative glucose metabolism to change into a non-oxidative glucose metabolism. This, in turn, causes a decrease in pH, acidosis, and a low oxidoreduction potential. It also impairs phagocytosis and activates proteolytic enzymes which create ideal conditions for the growth of anaerobic bacteria. The obtained results indicate that the pH, pO2 and pCO2 may be used to differentiate bacterial peritonitis from ascites of other etiologies.