• Japanese dog breeds;
  • Na-K pump;
  • pseudohyperkalemia;
  • red blood cell


Canine RBCs are expected to have high sodium and low potassium (LK) concentrations. However, some dogs have a low sodium and high potassium (HK) phenotype due to a Na-K pump in the mature RBC membrane. Awareness of this particularity avoids misinterpretation of hyperkalemia in affected dogs.


The purpose of this study was to compare the CBCs, serum biochemistry profiles, urinalysis data, and electrocardiography data in HK and LK Akita dogs.


In this study, the intra-RBC potassium (KRBC) was measured in 48 healthy adult Akita dogs. The HK group included dogs with KRBC concentration at least 5-fold that of plasma, while the LK dogs served as controls.


The HK phenotype was determined in 10 dogs (21%). With the exception of higher plasma potassium concentrations in the HK group compared with LK controls (6.6 mmol/L vs 4.4 mmol/L, P < .001), there were no other differences in serum biochemistry variables. In hematology, mean HGB concentration (13.5 vs 15.9, P < .001), PCV (42.9 vs 46.7, P = .009), RBC (6.1 vs 7.4, P < .001), and MCHC (31.3 vs 34.0, P < .001) were significantly lower in the HK group, while MCV (70.0 vs 63.4, P < .001) was higher compared with the LK controls. There were no significant differences in urinalysis or electrocardiography data between groups.


HK Akita dogs showed significant differences in several hematologic variables, as well as higher plasma potassium concentration. Therefore, the HK phenotype should be considered in the interpretation of these variables in this breed.