A 9-year-old Golden retriever presented with a 10-day history of rapidly progressing lethargy, intermittently falling over, pacing aimlessly, abnormal behaviour, and ataxia on all four limbs. The dog was administered paracetamol and prednisolone 0.5 mg/kg BID for a few days but did not respond by the time of the MRI.

MR study revealed diffuse patchy contrast enhancement of the meninges extending to the sulci throughout the forebrain, caudal brainstem, and cranial cervical spinal cord as well as ependymal lining of the lateral ventricle in its most rostral part, visible as well as mild hyperintensity on T2-FLAIR. The diffuse/patchy meningeal and ependymal contrast enhancement affecting the brain and cranial cervical spinal cord is suggestive of surface-related disease process with in order of likelihood 1) infectious CNS disease (especially fungal disease in dogs or bacterial - and viral disease in cats with FIP), 2) sterile inflammatory CNS disease (although very unlikely as conditions such as MUO do not cause ependymitis) and 3) diffuse neoplastic process (also considered extremely unlikely to affect the ependymal lining). CSF on this dog showed a total protein of 175 mg/dl and, a nucleated cell count of 689/ul consisting mostly of neutrophils with fungal organisms compatible with Cryptococcus spp. Cryptococcal antigen was also positive.

Courtesy of Dr. Lorena Martinez.

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