title: Serum C-reactive protein as a diagnostic biomarker in dogs with bacterial respiratory diseases.
abstract: BACKGROUND
  C-reactive protein (CRP) is a major acute-phase protein in dogs. Serum concentrations are low in healthy animals, but increase rapidly after inflammatory stimuli.
  
  
  OBJECTIVE
  The aim of the study was to investigate CRP concentrations in various respiratory diseases of dogs and to determine if CRP can be used as a biomarker in the diagnosis of bacterial respiratory diseases.
  
  
  METHODS
  A total of 106 privately owned dogs with respiratory diseases (17 with bacterial tracheobronchitis [BTB], 20 with chronic bronchitis [CB], 20 with eosinophilic bronchopneumopathy [EBP], 12 with canine idiopathic pulmonary fibrosis [CIPF], 15 with cardiogenic pulmonary edema [CPE], and 22 with bacterial pneumonia [BP]) and 72 healthy controls.
  
  
  METHODS
  The study was conducted as a prospective cross-sectional observational study. CRP was measured in serum samples. Diagnosis was confirmed by clinical and laboratory findings, diagnostic imaging, and selected diagnostic methods such as cytological and microbiological analysis of respiratory samples, echocardiography, and histopathology.
  
  
  RESULTS
  Dogs with BP had significantly higher CRP concentrations (median, 121 mg/L; interquartile range, 68-178 mg/L) than dogs with BTB (23, 15-38, P = .0003), CB (13, 8-14, P < .0001), EBP (5, 5-15, P < .0001), CIPF (17, 10-20, P < .0001), or CPE (19, 13-32, P < .0001) and healthy controls (14, 8-20, P < .0001). Dogs with BTB had significantly higher CRP concentrations than dogs with CB (P = .001) or EBP (P < .0001) and healthy controls (P = .029).
  
  
  CONCLUSIONS
  These results indicate that CRP has potential for use as an additional biomarker, especially in the diagnostics of BP.
authors.affiliation: Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Finland.
authors.forename: S J
authors.initials: SJ
authors.lastname: Viitanen
authors.forename: H P
authors.initials: HP
authors.lastname: Laurila
authors.forename: L I
authors.initials: LI
authors.lastname: Lilja-Maula
authors.forename: M A
authors.initials: MA
authors.lastname: Melamies
authors.forename: M
authors.initials: M
authors.lastname: Rantala
authors.forename: M M
authors.initials: MM
authors.lastname: Rajamäki
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis*; D002097:C-Reactive Protein / Q000032:analysis*; D003430:Cross-Sectional Studies; D004283:Dog Diseases / Q000175:diagnosis / Q000382:microbiology*; D004285:Dogs; D005260:Female; D008297:Male; D011446:Prospective Studies; D012140:Respiratory Tract Diseases / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein
keywords: Acute-phase protein; Canine; Pneumonia