It is possible that dogs with PDE have certain DLA subtypes that prevent them from responding to infectious agents appropriately. Without pedigree information, the researching studies can not be run meaningfully. Clinical signs almost always reflect involvement of the cerebrum of the brain, with generalized seizures consistently occurring, together with features such as circling, head pressing, and assymetric weakness and visual deficits. Peripheral blood hematological and chemical parameters are generally normal. As is typical of almost all cases of encephalitis, regardless of cause, white corpuscles are generally increased in spinal fluid samples from affected dogs.
Signs occur and progress acutely.
However, long term recovery or cure has not been described, as far as is known. Grey and white matter equally affected in the principal pathologic study of this condition. Based on fewer cases white matter has been preferentially affected. Causative organisms have not been identified, although persistent herpesvirus infection was proposed as a potential cause in the original study. Marked neuronal necrosis and leucoencephalitis are noted, with cavation occurring in more chronically affected dogs.