Evaluation of the zetacrit and zeta sedimentation ratio in dogs.

The Wintrobe erythrocyte sedimentation rate (ESR) has been used in animals and persons as a screening test for inflammatory disease and as a monitor for disease progression in individuals. Now, the zetacrit (ZC) and zeta sedimentation ratio (ZSR) are suggested as suitable rapid laboratory tests to replace the ESR in dogs. In 65 dogs, a strong inverse correlation between ESR and ZC was observed (r = -0.961, P less than 0.05). Significant correlations of similar magnitude between ZC and hematocrit (r = 0.587, P less than 0.05) and ESR and Hct (r = 0.569, P less than 0.05) were observed. In addition, influences of various protein fractions, such as fibrinogen, globulin, and albumin, on the ESR and ZC were evaluated and found to be of similar magnitude. These data indicate that ESR and ZC are equivalent methods for determining erythrocyte sedimentation rates in dogs. A strong correlation (r = 0.900, P less than 0.05) between Wintrobe ESR, adjusted for the effect of Hct (ESRHct), and ZSR was observed. The influence of plasma proteins on ESRHct and ZSR was of similar magnitude. However, a weak yet significant correlation between ESRHct and the microhematocrit remained (r = 0.291, P less than 0.05). Data indicate that the latter more effectively factors out the influence of Hct on sedimentation.