Viral infections in dogs have a normal total white blood cell count or an increased percentage of lymphocytes. In bacterial infections, the total white blood cell count is elevated, or the neutrophil ratio is elevated, and the difference between the two is most likely to be made by examination of the cerebrospinal fluid. In viral encephalitis, the total white blood cell count is low and the protein level is low, while in bacterial encephalitis, the total white blood cell count is high, which is the main differentiator.
