title: Brain abscesses as a metastatic manifestation of strangles: symptomatology and the use of magnetic resonance imaging as a diagnostic aid.
abstract: BACKGROUND
  The occurrence of unexpectedly high numbers of horses with neurological signs during two outbreaks of strangles required prompt in-depth researching of these cases, including the exploration of magnetic resonance imaging (MRI) as a possible diagnostic technique.
  
  
  OBJECTIVE
  To describe the case series and assess the usefulness of MRI as an imaging modality for cases suspected of space-occupying lesions in the cerebral cavity.
  
  
  METHODS
  Four cases suspected of suffering from cerebral damage due to Streptococcus equi subsp. equi infection were examined clinically, pathologically, bacteriologically, by clinical chemistry (3 cases) and MRI (2 cases). In one case, MRI findings were compared to images acquired using computer tomography (CT).
  
  
  RESULTS
  In all cases, cerebral abscesses positive for Streptococcus equi subsp. equi were found, which explained the clinical signs. Although the lesions could be visualised with CT, MRI images were superior in representing the exact anatomic reality of the soft tissue lesions.
  
  
  CONCLUSIONS
  The diagnosis of bastard strangles characterised by metastatic brain abscesses was confirmed. MRI appeared to be an excellent tool for the imaging of cerebral lesions in the horse.
  
  
  CONCLUSIONS
  The high incidence of neurological complications could not be explained but possibly indicated a change in virulence of certain strains of Streptococcus equi subsp. equi. MRI images were very detailed, permitting visualisation of much smaller lesions than demonstrated in this study and this could allow prompt clinical intervention in less advanced cases with a better prognosis. Further, MRI could assist in the surgical treatment of brain abscesses, as has been described earlier for CT.
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University Yalelaan 12, PO Box 80153, 3508 TD Utrecht, The Netherlands.
authors.forename: T J P
authors.initials: TJ
authors.lastname: Spoormakers
authors.forename: J M
authors.initials: JM
authors.lastname: Ensink
authors.forename: L S
authors.initials: LS
authors.lastname: Goehring
authors.forename: J P
authors.initials: JP
authors.lastname: Koeman
authors.forename: F
authors.initials: F
authors.lastname: Ter Braake
authors.forename: R H
authors.initials: RH
authors.lastname: van der Vlugt-Meijer
authors.forename: A J M
authors.initials: AJ
authors.lastname: van den Belt
mesh_terms: D000818:Animals; D001922:Brain Abscess / Q000175:diagnosis / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D004196:Disease Outbreaks / Q000662:veterinary; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology; D006736:Horses; D015994:Incidence; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D013290:Streptococcal Infections / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D018502:Streptococcus equi / Q000302:isolation & purification / Q000472:pathogenicity; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000662:veterinary; D014774:Virulence