Our study showed a significantly higher serum CRP concentration in ISACHC III heart failure patients in comparison with ISACHC II, ISACHC I and healthy dogs, although the median value of CRP concentration in ISACHC III group did not exceed the upper value of reference range [31] and more than a half of the patients in this group had CRP concentrations within the reference range. The gene discussed is CRP; the disease is heart failure.