Enterococcus spp. Meningoencephalitis, Ventriculitis, and Hypophysitis in a Dog

A 13 yr old spayed female Yorkshire terrier was hospitalized for a dull mentation, anorexia, presumptive gastroenterocolitis, and a suspected gastrointestinal bleed with melena. Despite supportive therapy, the patient's clinical signs persisted. Throughout hospitalization, the patient became progressively dull to stuporous with a progressive hypernatremia. On day 3 of hospitalization, the patient acutely developed neurological signs with a neuroanatomical localization consistent with a process at the caudal cranial fossa. Per the owner's wishes, the patient was euthanized with necropsy performed. Histopathology revealed a suppurative meningoencephalitis, ventriculitis, hypophysitis, otitis interna, and an ulcerative pharyngitis. Aerobic culture collected from the area of the pituitary gland grew an Enterococcus spp. Enterococcal meningoencephalitis is rare in humans but has not been reported in veterinary medicine. In future cases of canine bacterial meningitis, Enterococcus spp. should be considered. Because of the inherent resistance patterns of Enterococcus spp., targeted antibiotic selection would be required for treatment.