Hematological parameters and immune response characteristics in canine chlamydiosis

Chlamydiosis is a zoonotic infectious disease caused by bacteria of the genus Chlamydia, characterized by a wide range of clinical manifestations. This study investigates hematological changes and describes certain immunological mechanisms in various clinical forms of the disease. The aim of the research was to analyze hematological parameters and clinical signs in dogs affected by chlamydiosis to determine the relationship between immunological changes and the clinical course of the disease, thereby improving diagnosis and treatment strategies. The study was conducted on 36 dogs diagnosed with respiratory, intestinal, genital, dermatological, and polyarthritis forms of chlamydiosis, with 10 clinically healthy dogs included as a control group. Clinical examinations assessed appetite, behavior, body condition, spatial positioning, tail and ear posture, gaze, coat and skin condition, pupil size, mucous membranes, dental arcade, respiratory movements, body temperature, and heart rate. Hematological parameters were measured using the MicroCC-20 plus analyzer. Biochemical indices were recorded using the HTI BioChem FC-120 (USA) automatic biochemical analyzer. Ultrasonographic examinations were performed with the Logiq P6 PRO system. Fluorographic screening was conducted using the Univet X-ray apparatus. Immunological studies of biological material from dogs with chlamydiosis were carried out at the “Bald” diagnostic laboratory in Kyiv. According to the study results, the most severe course of chlamydiosis was observed in dogs with respiratory syndrome, characterized by hyperthermia, tracheobronchitis, increased pulmonary pattern intensity, and thickening of bronchial walls. Hematological alterations, including leukocytosis, lymphocytosis, and monocytosis, indicate an intense phagocytic immune response of the host organism. The polyarthritis form of chlamydiosis exhibited an immunological pattern resembling an autoimmune response, radiographically confirmed by periostitis in the mid and upper regions of the humerus. Hematologically, segmental neutropenia, lymphocytosis, and monocytosis were recorded. Biochemical alterations, such as hyperproteinemia (P < 0.05), served as markers of systemic inflammatory processes. Elevated alanine aminotransferase activity (P < 0.05) and decreased creatinine levels suggested disruptions in cellular metabolism and joint inflammation. In the intestinal form of chlamydiosis, intestinal barrier dysfunction and systemic intoxication were confirmed by hyperbilirubinemia and hyperproteinemia in the blood serum of affected dogs. The dermatological form showed a significant increase in segmented neutrophils (P < 0.001). The genital form was accompanied by lymphocytosis, bilirubinemia, and increased alanine aminotransferase activity. The findings confirm the correlation between clinical forms of canine chlamydiosis and changes in hematological and biochemical blood parameters, reflecting specific immune responses to the infection. The obtained data may serve as additional, though nonspecific, diagnostic markers aiding in the more precise identification of different chlamydiosis forms in dogs.