EN
Necrotizing menigoencephalitis of unknown etiology has been reported in Yorkshire terriers in Switzerland, Japan, Italy and the United States. A 4-year old male Yorkshire terrier was referred to the clinic of Veterinary Medicine Faculty in Olsztyn. The dog had exhibited symptoms of cervical hyperesthesia, visual deficits, ataxia and proprioceptive deficiency in all limbs for the previous 3 weeks. Clinical findings revealed chronic, progressive neurological signs and were consistent with multifocal, diffuse lesions involving the cerebrum and brainstem. The total blood count and biochemistry profiles were normal. Elevated protein concentrations and mononuclear pleocytosis were demonstrated following cerebrospinal fluid evaluation. Multifocal, extensive areas of decreased opacity throughout the cerebral hemispheres, asymmetric ventromegaly, and lack of contrast enhancement were evident on computer tomography images of the dog's brain. No mass effect was seen. Computed tomography abnormalities together with neurological examinations and cerebrospinal fluid analysis should facilitate a positive diagnosis of necrotizing meningoencephalitis in Yorkshire terriers