Meningoencephalitis with cerebral abscessation in a 2-year old Icelandic Pony filly

A 2-year old Icelandic Pony filly presented on June 12, 2012 with a chief complaint of blindness of acute onset. She had been previously hospitalized for recurrent fever and colic, mild pleuropneumonia, head turn, neck stiffness and ataxia. She had seemingly responded to a course of trimethoprim-sulfonamide and flunixin meglumine until presentation for blindness. The patient alternated between depression with head pressing and compulsive circling to the left. Examination revealed tachycardia, neck stiffness, and intact pupillary light reflexes with a menace deficit in the right eye. Initial diagnostics were unrewarding and the patient was referred for an MRI. A left cerebral abscess was diagnosed, likely due to a bacterial, hematogenous source. Treatment with antibiotics and neuroprotectants was unsuccessful. A craniotomy was attempted but the patient died during anesthetic induction. The diagnosis, treatment and prognosis of equine brain abscesses are discussed