Canine C-reactive protein: Isolation, immunoturbidimetric assay adaptation and evaluation of serum concentration in normal dogs and in dogs with an inflammatory response

C-reactive protein (CRP) in the canine species was investigated. Canine CRP was successfully isolated from acute phase sera by three consecutive liquid chromatography steps.

A reliable immunoturbidimetric assay for canine CRP utilizing a Roche COBAS FARA analyzer was developed. Calibration curves were established and method quality was evaluated. The assay was found to be rapid, accurate and precise over its analytical range.

The immunoturbidimetric assay was used to measure serum CRP concentration in 5 dogs undergoing ovariohysterectomies and in 67 dogs with inflammation as defined by the presence of at least 1.0 $\times$ 10$\sp9$/L band neutrophils in circulation. In the dogs undergoing surgery, the mean serum CRP concentration was significantly increased above baseline concentrations by 28 hours post-operatively, and declined to baseline concentrations by the fifth post-operative day. The dogs with inflammatory leukograms had serum CRP concentrations ranging from 4.7 to 334.3 mg/L. A significant difference in serum CRP concentrations was found between this group of dogs and the 44 normal dogs using a Mann-Whitney rank sum tests. A correlation coefficient (r) comparing band neutrophil counts with CRP concentrations was 0.343, which was significant. (Abstract shortened by UMI.).