Long-term survival in a dog with meningoencephalitis and epidural abscessation due to Actinomyces species.

A 2-year-old, female spayed Golden Retriever dog was presented to The Ohio State University Veterinary Medical Center for evaluation of ataxia, cervical pain, 1 episode of acute collapse, dull mentation, and inappetence. Physical examination revealed an elevated temperature of 39.7°C and severe cervical pain. Blood work revealed a mature neutrophilia. Cerebrospinal fluid (CSF) analysis revealed nondegenerative neutrophilic pleocytosis with no infectious agents. A presumptive diagnosis of steroid-responsive meningitis-arteritis was made, and corticosteroid therapy was started. The patient improved initially but experienced a vestibular episode characterized by falling and vertical nystagmus. A magnetic resonance imaging of the brain revealed an epidural abscess in the cervical vertebral canal and diffuse meningeal enhancement in the brain and cranial cervical spine. Abscess drainage revealed degenerate neutrophils and several filamentous, branching organisms. Culture of the initial CSF using an enrichment broth revealed growth of a Gram-positive organism 5 days after fluid collection. The isolate was identified by partial 16S ribosomal DNA sequencing as Actinomyces spp. The patient was successfully treated with long-term antibiotics. Our study reports the long-term survival after medical treatment of bacterial meningoencephalitis and epidural abscessation due to Actinomyces sp. infection in a dog. Bacterial meningoencephalitis should be included as a differential diagnosis in patients with cervical pain and fever, even when a nondegenerative neutrophilic pleocytosis is found on CSF analysis. Culture of the CSF with use of an enrichment broth should be considered in all cases of neutrophilic pleocytosis to rule out infections of the central nervous system.