The stray dog population has no access to veterinary care and most of them are highly infested with ticks. Ticks can transmit various parasitic, viral and bacterial diseases to their host dogs as well as can also lead to various zoonotic infections in humans exposed to them as Lyme disease and skin rashes. Incidence of tick-transmitted bacterial infection Borreliosis is very high in tick infested dogs, especially in hot weather. The current crosssectional study was carried out for the first time to detect the incidence of borrelia infection in tick-infested dogs in Sharqia province (Zagazig, Egypt) and revealed that female dogs (16.3%) were more heavily infected than male dogs (11.1%), while infected young dogs (20.5%) outnumbered infected adults (6.8%). The local strain of the dog’s infection was (53.8%) compared to other imported strains. Controlling ticks is considered most important for the eradication of seasonal and zoonotic diseases and to prevent further human infections. ELISA was used as a chemical test with an immunological relationship for IgM in our cross-sectional studies for various serum samples. IgG titer level detection at different stages of disease and infection. The most common diseases transmitted by tick to human and animals in mixed