In dogs, C-reactive protein (CRP) is a major acute phase protein produced in response to inflammation and the release of cytokines.   It has been shown to be an effective measure of general inflammation.  Inflammation is involved in both the initiation and propagation of many disease processes.  While non-specific, it is very sensitive to developing problems.

In a large study of healthy dogs [9] CRP was measured and then the dogs were followed over a 6-month time period.  All-cause mortality was recorded and sorted by CRP concentration.  As demonstrated in the table, there is an increasing death rate as a function of CRP underscoring the importance of monitoring and resolving chronic inflammation.


Effective uses for CRP

Wellness Screening

While CRP is non-specific, it is very sensitive to systemic inflammation.  Its non-specificity is actually a benefit for a general wellness screen as one test can identify inflammation due to a wide variety of diseases/causes.  Low levels then become a rule out for serious disorders and moderate to high levels become a call-to-action for further diagnostic workups.

VDI offers intelligent diagnostics with all CRP wellness tests intended to help narrow down the likely source. Learn more here.

Pre-Surgical

CRP is an excellent complement to a pre-surgical blood test.  Dogs in an inflammatory state are at higher risk for post-surgical complications due to coagulation complications and the potential for organ failure due to SIRS.  Inflammation is known to affect coagulation.  Initially, inflammation induces a patient into a hypercoagulation state and with increasing severity advances to systemic hypocoagulation.  Comparing CRP to the activated clotting time (ACT), it was found that with increasing levels of inflammation, clotting times increased significantly [7].  Knowing the inflammatory state of the dog before surgery serves as a valuable aid in patient management.

Post Operative

CRP can be helpful in monitoring post-operative recovery.  If there are no post-op complications, CRP begins to decrease within 3-5 days post-surgery, and then return to normal levels within one to two weeks[5,8].  If post-operative recovery is complicated by infection, CRP concentrations will not begin to decrease as expected within 3-5 days post-op.

CRP is reported quantitatively in mg/L as:
Optimum: ≤ 2.0
Normal: ≤ 3.9
Low Inflammation: 4 – 9.9
Moderate Inflammation: 10 – 39.9
High Inflammation: ≥ 40


References:

  1. Matijatko V., et. al. Evidence of an acute phase response in dogs naturally infected with Babesia canis. Vet Parasit 2007:144:242-250
  2. Nakamura, M. et. al. C-Reactive protein concentration in dogs with various diseases. J Vet med Sci 2008:127-131
  3. Eckersall, P., et. al. Acute phase proteins: biomarkers of infection and inflammation in veterinary medicine. Vet J 2010:185:23-27
  4. Hayashi, S., et. al. A comparison of the concentrations of C-reactive protein and alpha1-acid glycoprotein in the serum of young and adult dogs with acute inflammation. Vet Res Comm 2001:25:117-126
  5. Dabrowski, R., et. al. Changes in CRP, SAA and haptoglobin produced in response to ovariohysterectomy in healthy bitches and those with pyometra. Therigenology 2006:doi:10.1016/j
  6. Fransson, B., et. al. C-reactive protein in the differentiation of pyrometra from cystic endometrial hyperplasia/mucometra in dogs. J Am Ani Hosp Assoc 2004:40:391-399
  7. Cheng, T. et. al. Relationship between assays of inflammation and coagulation: a novel interpretation of the canine activated clotting time. Can J Vet Res 2009:73:97-102
  8. Galexowski, A., et. al. C-reactive protein as a prognostic indicator in dogs with acute abdomen syndrome. J Vet Diag Invest 2010:22:395-401
  9. Selting,K., et al. 2013. Serum thymidine kinase 1 and C-reactive protein as biomarkers for screening clinically healthy dogs for occult disease. Veterinary and Comparative Oncology. doi: 10.1111/vco.12052