Subdural hygroma secondary to presumptive eosinophilic meningoencephalitis in a dog

Abstract An 8‐year‐old, female, neutered Lurcher‐cross dog presented with acute obtundation and cervical hyperaesthesia. Magnetic resonance imaging revealed a moderate, left‐sided, crescent‐shaped expansion of the subdural space with fluid and raised intracranial pressure. Decompressive craniectomy revealed clear fluid, clinical and histopathological analysis was negative for infectious agent, favouring the diagnosis of subdural hygroma. The dog's neurological signs relapsed 1 month after discontinuation of immunomodulatory treatment, presenting with cranial nerve deficits and cervical hyperaesthesia. Magnetic resonance imaging revealed further accumulation of subdural fluid. Cerebrospinal fluid analysis revealed eosinophilic pleocytosis. Reintroduction of immune‐modulatory treatment led to the resolution of clinical signs. The subdural hygroma was suspected to be secondary to presumptive eosinophilic meningoencephalitis.