The paper presents the results of a morphological study of the blood of dogs of service breeds, in which signs of chronic kidney disease were detected. Often, the pathological condition of the kidneys develops as a secondary process due to intoxication of endo- or exogenous origin, infectious and invasive diseases. The danger of chronic kidney disease is that the owners or maintenance staff notice the appearance of animal health problems already in the late stages, when conservative treatment most often cannot give positive dynamics. During a clinical blood test, it was found that the dogs of the experimental group (patients) had erythropenia and hypochromemia, which were most likely associated with impaired renal function, and, as a consequence, decreased erythropoietin secretion. Of course, the decrease in the number of red blood cells caused a significant decrease in the hematocrit value to the level of 31.5 ± 5.6 l/l, which was 26.9% lower than the level of this indicator in healthy animals. When analyzing the leukogram, a picture of neutrophilia with a shift of the nucleus to the right was noted. The percentage of lymphocytes in the leukogram of sick dogs was 2.7 times lower than in healthy dogs, which can be considered a relative change in the percentage due to increased neutrophil counts. If we talk about the total content of leukocytes in the blood, no significant changes were found. Thus, during the study of the blood of dogs of service breeds with signs of chronic kidney disease, signs of hypochromic anemia were established.