Background and Aim:Blood parasite infections such as anaplasmosis, babesiosis, and ehrlichiosis are commonly found in domestic dogs, which adversely influence their health. Many dogs are infected with multiple blood parasites that cause more severe diseases than a single infection. This study aimed to investigate the effect of multiple blood parasite infections on the hematological profiles of dogs at a shelter in Southern Thailand.Materials and Methods:The blood samples from 122 dogs were collected to assess the hematology profiles of uninfected, single-infected, and multiple blood parasite-infected dogs. The results were compared using Kruskal–Wallis test and Dwass–Steel–Critchlow–Fligner pairwise comparisons. The infections were confirmed by polymerase chain reaction.Results:The results showed that all the infected dogs had significantly lower red blood cell (RBC) count, hemoglobin (HB), hematocrit (HCT), and platelet count (PLT) than the uninfected dogs. Although the dogs with triple infection had lower RBC, HB, HCT, and PLT than those with double and single infections, the difference was not statistically significant.Conclusion:We proposed that triple blood parasite infection withAnaplasma platys,Babesia vogeli, andEhrlichia caniscaused more severe disease than double and single infections. Evaluating the hematological profiles of dogs naturally infected with single, double, and multiple blood parasite infections without clinical signs can enhance their health and welfare.