title: Meningitis and meningoencephalomyelitis in horses: 28 cases (1985-2010).
abstract: OBJECTIVE
  To describe clinical and clinicopathologic findings and outcome of horses with meningitis and meningoencephalomyelitis.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  28 horses.
  
  
  METHODS
  Medical records of horses admitted to the hospital during a 25-year period were reviewed. Horses with a definitive diagnosis of meningitis or meningoencephalomyelitis were included in this study. Information extracted from the medical records included signalment, history, reason for admission, clinical signs, results of clinicopathologic testing and diagnostic procedures, treatment, outcome, and necropsy findings.
  
  
  RESULTS
  22 horses had confirmed infectious disease (19 bacterial, 2 parasitic, and 1 fungal), 4 had suspected infectious disease on the basis of CSF cytologic examination findings, and 2 had noninfectious meningitis or meningoencephalomyelitis. Trauma of the head and vertebral column with disruption of the blood-brain barrier and local ascending or hematogenous spread were the most common routes of infection. Common neurologic signs included abnormal mental status, cranial nerve deficits, vestibular dysfunction, ataxia, tetraparesis, and apparent neck pain. Common hematologic abnormalities included leukocytosis, neutrophilia, lymphopenia, and hyperfibrinogenemia. Cytologic examination of CSF samples revealed moderate to marked suppurative inflammation. Mortality rate was 96.4%. Microbial culture of CSF yielded bacterial growth in 15 of 23 horses (before death [2 horses], after death [11], and both [2]).
  
  
  CONCLUSIONS
  Results suggested that meningitis and meningoencephalomyelitis are uncommon disorders in horses. Infectious disease was more common than noninfectious disease. Local trauma, ascending infection, or hematogenous spread of infection were the most common causes of meningitis or meningoencephalomyelitis. Neurologic deficits, neutrophilia, lymphopenia, hyperfibrinogenemia, and CSF with neutrophilic pleocytosis were common findings in affected horses.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
authors.forename: Balazs
authors.initials: B
authors.lastname: Toth
authors.forename: Monica
authors.initials: M
authors.lastname: Aleman
authors.forename: Nora
authors.initials: N
authors.lastname: Nogradi
authors.forename: John E
authors.initials: JE
authors.lastname: Madigan
mesh_terms: D000818:Animals; D005260:Female; D006734:Horse Diseases / Q000134:cerebrospinal fluid / Q000209:etiology* / Q000401:mortality; D006736:Horses; D008297:Male; D008581:Meningitis / Q000134:cerebrospinal fluid / Q000209:etiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D008590:Meningoencephalitis / Q000134:cerebrospinal fluid / Q000209:etiology / Q000401:mortality / Q000473:pathology / Q000662:veterinary*; D012189:Retrospective Studies