Unusual MRI features in a case of presumed canine tick‐borne meningoencephalomyelitis

Abstract A 7‐year‐old, standard, wire‐haired dachshund presented with quickly progressive multifocal central nervous system signs, which localised to the brainstem and cervical myelopathy, including reduced cervical and thoracic limb muscle tone and withdrawal reflexes. Magnetic resonance imaging revealed bilateral, approximately symmetric, T2‐weighted hyperintense, T1‐weighted iso‐ to hypointense, strongly enhancing lesions involving the white and grey matter of the cerebrum, brainstem and cervical spinal cord with no perilesional oedema. Cerebrospinal fluid analysis identified a markedly increased protein concentration and a moderate mixed pleocytosis, compatible with a viral infection. Tick‐borne encephalitis was suspected based on a high immunoglobulin M serology titre. Euthanasia was performed 2 days after presentation due to lack of clinical improvement. Previously reported magnetic resonance imaging changes include bilateral grey matter lesions that are minimally or non‐contrast‐enhancing; this case report provides the first description of strongly contrast‐enhancing lesions involving the white matter on magnetic resonance imaging in a case of suspected canine tick‐borne meningoencephalomyelitis.