Determination of calcium fractionation in dogs with chronic renal failure.
OBJECTIVE
To determine concentrations of calcium (total [tCa], ionized [iCa], protein-bound [pCa], and complexed [cCa]) in dogs with chronic renal failure (CRF).


METHODS
23 dogs with CRF.


METHODS
Serum calcium was fractionated by use of a micropartition system. Total calcium and iCa concentrations and pH were measured in unfractionated serum, and tCa concentration was measured in the ultrafiltrate. The pCa fraction was calculated by subtracting tCa of the ultrafiltrate from tCa concentration of unfractionated serum. The iCa concentration in unfractionated serum was subtracted from tCa concentration in the ultrafiltrate to determine the concentration of cCa.


RESULTS
Concentrations of tCa, iCa, pCa, and cCa had wide ranges among dogs with CRF Dogs with significantly low tCa concentration (770 +/- 1.73 mg/dL) had cCa concentration (0.76 +/- 0.38 mg/dL) within reference range, whereas dogs with reference range to high tCa concentration (10.85 +/- 1.13 mg/dL) had significantly high cCa concentration (2.62 +/- 1.04 mg/dL). There was no significant difference in iCa or pCa concentrations between groups.


CONCLUSIONS
Concentrations of tCa, iCa, cCa, and pCa varied widely in dogs with CRF Overall, cCa concentration was high, although subpopulations differed in cCa and tCa concentrations. Differences in tCa concentration were primarily attributable to differences in cCa fraction.
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D001806:Blood Urea Nitrogen; D002118:Calcium / Q000097:blood / Q000378:metabolism*; D002245:Carbon Dioxide / Q000097:blood; D002712:Chlorides / Q000097:blood; D002784:Cholesterol / Q000097:blood; D003404:Creatinine / Q000097:blood; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D006863:Hydrogen-Ion Concentration; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D010758:Phosphorus / Q000097:blood; D014462:Ultrafiltration / Q000662:veterinary
D001798:Blood Proteins; D002712:Chlorides; D002245:Carbon Dioxide; D010758:Phosphorus; D002784:Cholesterol; D003404:Creatinine; D002118:Calcium