Pyometra is a common disease in intact bitches characterized by uterine bacterial infection with the accumulation of purulent exudate within the lumen, leading to subsequent systemic illness. The aims of the present study were to investigate the incidence of the disease in relation to age and to evaluate the hematological findings in the diagnosis of pyometra. Data presented in this study show that the occurrence of pyometra in the study was more frequent in animals at the age of 8 (16.7%) with an average age estimated at 8 years, 7 months, and 3 days. The evaluation of the hematological parameters revealed that leukocytosis, neutrophilia and monocytosis were shown, indicating a great inflammatory response. However, there was a significant decrease in Hb, TEC and PCV, with values suggesting an anemic condition in affected animals due to the loss of erythrocytes into the lumen of uterus. This study provides data on the age-related difference in the incidence of pyometra. In addition, the blood parameters could serve as a good diagnostic method for the occurrence of pyometra and increase survival rates.