Borrelia burgdorferi, the causative agent of Lyme disease, is transmitted to horses and other mammals by infected Ixodes ticks, often called “deer ticks”. In Lyme endemic areas, B. burdorferi infection in horses is common and a low percentage of infected horses will develop clinically apparent Lyme disease. Neuroborreliosis, or more aptly referred to as Neurologic Lyme disease, is a neurologic form of Lyme disease occurs in horses with most cases diagnosed by autopsy. The ante-mortem diagnosis of Neurologic Lyme disease in horses is difficult as the disease can mimic several other diseases of the nervous system.