Hyperglycemia is a common feature of patients with sepsis. The impact of hyperglycemia in mortality and morbidity of critically ill patients is controversial. In veterinary medicine this controversy is further fueled by the paucity of clinical data. Pyometra is an important cause of sepsis in dogs. Pyometra is a uterine inflammatory process, characterized by the accumulation of purulent secretion, which can cause massive release of bacterial endotoxins in the bloodstream. In this context, there is a stimulus to the release of cytokines, particularly the tumor necrosis factor and interleukin 6. These inflammatory substances induce neuroendocrine stimulation and the release of catecholamines and hormones, such as GH, cortisol, glucagon that cause hyperglycemia. This complex framework causes hyperglycemia due to the stimulus of glycogenolysis and gluconeogenesis, increased lipid and protein catabolism and peripheral insulin resistance. This study aims to assess whether the blood glucose concentrations of dogs with pyometra are changed. Blood glucose concentrations were measured on admission of 18 bitches with pyometra, during the period from February, 2008 to January, 2009. The diagnosis of pyometra was based on clinical signs, leukogram compatible with inflammatory or infectious process, sonographic evidence, and confirmed during surgery. Blood glucose concentration was accessed by means of a handheld blood glucose sensor. A dog was considered to be hypoglycemic if the blood glucose was < 80 mg/dL; normoglycemic if the blood glucose was between 80 mg/dL and 120 mg/dL; and hyperglycemic if the blood glucose was > 120 mg/dL. Hyperglycemia occurred in three dogs, while normoglycemia was observed in 12 dogs (~67%). Hypoglycemic was observed in three dogs. According to the results above most of the dogs had blood glucose concentrations within the normoglycemic range. Neither hypo-or hyperglycemia was a prominent feature of the dogs in this series. Studies involving a large number of animals are warranted to better understanding of the role of blood glucose disturbances in dogs with pyometra.