<i>Ehrlichia canis</i> Seropositivity in a Hospital-Based Dog Population in Kars (Türkiye): IFAT–ELISA Comparison and Associated Demographic, Clinical, and Hematological Findings

Background: Ehrlichia canis is a common tick-borne pathogen in dogs and may occur without clear clinical signs, complicating diagnosis. Serological methods such as indirect immunofluorescence antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) are therefore widely used. This study aimed to determine the seropositivity of E. canis in dogs from the Kars region of Türkiye and to evaluate associated demographic, clinical, and hematological findings. Materials and Methods: Blood samples were collected from 188 dogs of different ages, breeds, and clinical backgrounds presented to the Animal Health Education, Application, and Research Hospital of Kafkas University (Türkiye) for routine care or clinical complaints. Results: E. canis seropositivity was detected at 22.34% (42/188) by IFAT and 10.64% (20/188) by ELISA. Taking IFAT as the reference, ELISA showed 50% sensitivity, 100% specificity, and 87.14% diagnostic accuracy, with moderate agreement between tests (κ = 0.598). No statistically significant differences were found in hematological parameters between seropositive and non-dual-seropositive dogs ( p values ranged from 0.065 to 0.343). Among demographic and clinical variables, only age showed a significant association ( p = 0.008), with higher seropositivity in older dogs; however, this should be interpreted cautiously due to small subgroup sizes. Conclusion: The findings indicate notable exposure to E. canis in a hospital-based sample of dogs from the Kars region, even in the absence of clinical or hematological abnormalities. Serological testing alone reflects exposure rather than active infection. Using IFAT and ELISA together may provide a more cautious approach in identifying seroreactive animals, though not necessarily improving definitive diagnostic accuracy.