Uterine diseases are frequently present in everyday small animal practice. Although etiologically different, the diagnostic approach does not vary significantly. Radiography in cases of uterine disorders provides poor resolution among possible physiological and pathological conditions. Sometimes the phase of the sexual cycle also affects the X-ray image of the uterus. For this reason, it is strongly recommended to use ultrasound as the next tool to confirm X-ray suspicion, or separately as a relevant high-specificity test. The most common, serious disorders of uterine health in bitches are pyometra, pyometra of the uterine stump, cystic endometrial hyperplasia (CEH) and uterine neoplasia. All of them during the examination should be distinguished from the physiological state of the uterus depending on the stage of the sexual cycle. Pyometra are radiographically successfully diagnosed in slightly more than half of later confirmed cases, while cystic endometrial hyperplasia is radiographically distinguished in a negligible percentage of cases. This paper successfully presents ultrasonography of the abdominal cavity as the first method of choice in diagnosis, in terms of a quick and non-invasive way to get a diagnosis and reduce the risk for the patient. At the same time, the ultrasound examination reveals possible complications caused by diseases of the uterus.