C-Reactive Protein as a Diagnostic Marker in Dogs: A Review

Simple Summary C-reactive protein is a major positive acute phase protein in dogs. It is commonly used as a marker of inflammation that, although nonspecific, is highly sensitive. The high clinical value lies in its rapid response and relatively short half-life time; these qualities make the C-reactive protein a good therapeutic guide; among others, it can be used to determine when an antimicrobial therapy could be ceased. Various tests are available on the market and the measurement is becoming a part of routine biochemistry blood panels in many countries. Although it is very useful, especially in conjunction with white blood cell count or other acute phase response proteins measurements, it does not allow a complete evaluation as a single parameter. Acute phase response is a nonspecific reaction to disturbances in homeostasis during which the production of some Acute Phase Proteins (APPs) is stimulated; they are sensitive but nonspecific markers of systemic inflammatory processes. The major positive APP in dogs is the C-reactive protein (CRP). The dynamic of its concentration changes fast, rising and decreasing rapidly with the onset and removal of the inflammatory stimulus. It increases within the first 4-24 h after the stimulus and reaches up to a 50-100-fold increase of the baseline level. It has been documented that this APP's concentration is elevated during several diseases, such as pyometra, panniculitis, acute pancreatitis, polyarthritis, sepsis, immune-mediated hemolytic anemia, and neoplasia in dogs. In clinical practice, canine CRP is mostly measured to detect and monitor systemic inflammatory activity and the efficacy of treatments, because it is a more sensitive marker than shifts in leukocyte counts. Blood serum CRP concentration is becoming a part of routine biochemistry panels in many countries. In this article, changes in CRP concentration and its clinical application in healthy and diseased dogs are discussed.