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.Animals: A total of 106 privately owned dogs with respiratory diseases ( 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)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(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).Conclusion and Clinical Importance: These results indicate that CRP has potential for use as an additional biomarker, especially in the diagnostics of BP.

Measurement of serum C-reactive protein concentration for discriminating between suppurative arthritis and osteoarthritis in dogs

“…This is in line with the results of previous studies, in which serum CRP concentrations did not differ between dogs with septic and non-septic inflammatory disease [23, 30, 31]. Although specific situations may exist where serum CRP indeed could be helpful for predicting presence of bacterial infection, as suggested in dogs with respiratory disease [32], this is not generally applicable.…”

The Utility of Acute‐Phase Proteins in the Assessment of Treatment Response in Dogs With Bacterial Pneumonia

“…This finding is in agreement with previous reports describing CRP and SAA in dogs with BP. 10,18,45 Haptoglobin concentrations have not been reported previously, but because significant increases in serum Hp have been reported 24 hours after an inflammatory stimulus, increased concentrations also were expected in BP. 9 However, it must be emphasized that APPs are highly nonspecific inflammatory markers and, in addition to BP, increased concentrations may be encountered in a variety of disease processes.…”

“…A full clinical examination was performed, and thoracic radiographs as well as blood, fecal, and respiratory samples were obtained at presentation as previously described. 18 Thoracic radiographs were assessed by the same radiologist (AKL), who was blinded to the patient data. Bacterial pneumonia was diagnosed when typical acute signs (at least 3 of the following: fever, lethargy, dyspnea, tachypnea, cough) were observed and thoracic radiograph findings were compatible with BP (ie, an alveolar pattern or a moderate or severe bronchointerstitial or interstitial pattern).…”

“…Hematology, serum biochemistry, arterial blood gas analysis, blood cultures, and fecal analysis along with cytological and microbiological analysis of respiratory samples were performed as previously described. 18 Coagulation parameters prothrombin time (PT) and activated partial thromboplastin time (aPTT) were evaluated with commercial test kits for dogs, a,b . Serum samples obtained for APP analysis either were immediately analyzed or stored at À80°C until analyzed.…”

Acute phase proteins in diagnostics: more than expected

“…Some examples could be: -In dogs with clinical signs compatible with respiratory diseases, bacterial pneumonia was identified with a specificity of 100% when CrP was higher than 100 mg/L, compared to other respiratory diseases/syndromes had significantly lower CrP values, such as bacterial tracheobronchitis (23 mg/L), chronic bronchitis (13 mg/L), eosinophilic bronchopneumonitis (5 mg/L), canine idiopathic pulmonary fibrosis (17 mg/L) and cardiogenic pulmonary edema (19 mg/L) (Viitanen et al, 2013).…”