Idiopathic eosinophilic meningoencephalitis in a Dutch Warmblood gelding

Summary An increased content of eosinophils in cerebrospinal fluid (CSF) and eosinophilic infiltration of brain tissue are observed in eosinophilic meningoencephalitis (EME). After exclusion of various infectious diseases and further known causes of EME in other species, the diagnosis idiopathic EME was made at necropsy in the case reported here. To the authors' knowledge, this is the first report of idiopathic EME in a horse similar to the disorder occurring in dogs.