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Onderstepoort Journal of Veterinary Research

On-line version ISSN 2219-0635
Print version ISSN 0030-2465

Onderstepoort j. vet. res. vol.76 n.3 Pretoria  2009




The effect of pyridoxal-5-phosphate on serum alanine aminotransferase activity in dogs suffering from canine babesiosis



E.C. Myburgh; A. Goddard

Department of Companion Animal Clinical Studies, Section of Clinical Pathology, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110 South Africa




Accurate measurements of serum aminotransferase (ALT) activity in dogs relies on the endogenous pro-enzyme pyridoxal 5-phosphate (P5P). The purpose of this study was to determine whether the exclusion of P5P from the analytical method causes an underestimation of serum ALT activity in dogs suffering from babesiosis and in those manifesting evidence of hepatocellular damage, and to determine if anorexia causes sufficient P5P depletion to affect in vitro serum ALT activity. One-hundred-and-twenty healthy control dogs and 105 Babesia-infected dogs were included in the study. Two methods for ALT measurement were used: Method 1 included P5P, and Method 2 excluded P5P from the reaction mixture. Higher serum ALT activity was measured with Method 1 in the Babesia-infected dogs (P < 0.001), as well as in 14 dogs with suspected hepatocellular damage (P = 0.03). Duration of anorexia had no effect, irrespective of the method used. Although inclusion of P5P to the reaction mixture consistently resulted in higher measured serum ALT activity, the differences were too small to have led to incorrect diagnoses in the Babesia-infected dogs suspected of liver disease.

Keywords: Alanine aminotransferase, anorexia, babesiosis, liver disease, pyridoxal 5'-phosphate



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Accepted for publication 16 March 2009-Editor



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