Magnetic Resonance Imaging and Histopathological Findings as Diagnostic Tools for Detection of Canine Distemper Virus Infection in Dogs

Background: The canine distemper virus (CDV) causes a persistent infection within the central nervous system, resulting in a progressive, multifocal demyelinating disease. Magnetic resonance imaging (MRI) and brain histopathology are important correlates for evaluating disease progression in canine distemper. This study aims to assess magnetic resonance imaging and histopathological findings of canine distemper virus infection in dogs. Methods: This study included 82 dogs with a nervous form of CD virus, confirmed by reverse transcriptase polymerase chain reaction (RT-PCR), at the College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Selesih, Aizawl, Mizoram, between March 2022 and July 2025. Dogs with clinically positive canine distemper virus infection were subjected to magnetic resonance imaging of the brain under general anaesthesia and histo-pathological examinations. Result: The MRI findings of the T1W axial image showed hypointense signal in the right temporal lobe with a corresponding area showing hyperintense signal on T2W with loss of gray-white matter differentiation in CD-infected dogs. Gross pathology of the brain showed haemorrhages on the meninges and histopathological examination revealed spongiosis and degenerative ischemic changes in the cerebellar hemisphere, microgliosis and loss of neurons in the cerebrum in all the examined dogs.