Background: Anaplasma platys is an obligate intracellular rickettsial parasite with a particular tropism for platelets. It causes infectious cyclic thrombocytopenia in canines, which may be accompanied by clinical signs such as fever, petechial and ecchymotic hemorrhages. Given the absence of prior studies on A. platys infection in dogs in Iran, the present study aimed to investigate the frequency of this microorganism in stray dogs housed in animal shelters. Methods: Whole blood samples were collected from 100 dogs housed in various shelters. A smear was prepared from each blood sample, stained with Giemsa, and examined under a light microscope. The collected samples were placed in CBC tubes containing EDTA and stored at - 20°C until DNA extraction. DNA extraction was performed using the Denazist kit according to the manufacturer\\\'s protocol. A primary PCR was conducted using genus-specific set of primers of the 16S rRNA gene for Anaplasma agents. The DNA of the positive samples was then subjected to a second PCR using A. platys specific forward primer. PCR products were analyzed by agarose gel electrophoresis. Results: No morulae of the parasite were observed within the platelets during microscopic examination. In the molecular analysis, out of 100 samples, 22 showed evidence of infection with the Anaplasma genus, of which 5 were confirmed to be A. platys. Conclusion: The present study confirmed the presence of A. platys infection in shelter dogs around Mashhad, with an estimated frequency of approximately 5%. The infection was effectively detected using molecular techniques, while microscopic methods exhibited lower sensitivity and accuracy.

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