The article considers a clinical case of uterine fibroids in an East European Shepherd dog. The owners complained of uncontrolled urination in the animal, which was aggravated over the past three months, as well as an increase in the abdomen, refusal of active physical exertion, shortness of breath when going up and down stairs, and decreased activity. Appetite and thirst are unchanged. The age of the dog is 8.5 years, sex is female, not neutered, sexual cycles are not regular, the last estrus is more than a year ago. Examination of the studied animal showed obesity, shortness of breath, capillary filling rate - 1 second. Palpation - the abdomen is soft, there is discomfort during palpation of the abdominal organs, an attempt to urinate. In the study of blood: RBC - 7.9 * 1012 / l; WBC - 9.21 * 109 / l; HCT - 57.2%; Hb - 198 g/l (hyperchromemia); eosinophilia - 9%, lymphocytopenia - 12%; biochemical study of blood serum: AST - 60 IU / l, ALT - 41 IU / l, total protein - 78 g / l, albumins - 38 g / l, alkaline phosphatase - 50 IU / l, total bilirubin - 1.7 μmol / l, concentrations of calcium, potassium, sodium, chlorine, phosphorus - at the upper limit of the reference values. Urinalysis - biochemical - no deviations, pH - 5.5, sediment microscopy - granular cylinders - single, mucus ++, erythrocytes: 0-2-3 in PM, leukocytes: 1-2-1 in PM, crystals - a small amount , calcium oxalates. Ovariohysterectomy revealed a massive formation on the uterus on the right, densely elastic consistency, grayish-whitish color on the cut. Histological examination (eosin-hematoxylin staining) determined that the formation is benign - leiomyoma.