Usefulness of basic laboratory parameters for monitoring during the perianesthetic period for selected ophthalmic operations in mesaticephalic and brachycephalic dogs

The aim of this study was to compare the usefulness of laboratory diagnostic parameters dedicated for general anesthesia in brachycephalic and mesaticephalic dogs. The study was performed on two groups of dogs of 112 animals each, representing two different morphotypes, brachycephalic and mesaticephalic ones, which underwent general anesthesia with medetominidine, midazolam, propofol and isoflurane. Before and after anesthesia, the dogs underwent basic haematological and biochemical tests. In 18% of mesaticephalic dogs and 16% of brachycephalic dogs, the results of laboratory blood tests show a significant increase in the activity of liver enzymes: aspartate aminotransferase (AST), alanine phosphatase (ALT) and alkaline phosphatase (ALP), even though the animals showed no clinical signs other than those recognized in ophthalmologic examination. This demonstrates the presence of subclinical hepatic changes in these animals. Moreover, general anesthesia had a greater negative impact on liver function if liver enzyme values had exceeded certain levels before the anesthesia (AST > 61 U/L, ALT > 91 U/L). This made it possible to define new, useful upper limit values of AST and ALT for subclinical dogs before anesthesia that could lead to more serious complications of liver function after anesthesia. Among all the examined parameters, it is beneficial to monitor the activity of AST, ALT and ALP during the perianesthetic period. In the postanesthesia monitoring, creatinine concentration should also be included.