Plasma L-carnitine concentration in healthy dogs and dogs with hepatopathy

Background: L‐Carnitine has an essential role in lipid metabolism. Disturbances of L‐carnitine metabolism can influence the energy supply of the organism. L‐Carnitine is synthesized exclusively in the liver. Hence, we hypothesized that liver disease can influence L‐carnitine metabolism. Objectives: The goal of this study was to compare plasma L‐carnitine concentrations in dogs with different liver diseases of differing severity with the plasma L‐carnitine concentrations of healthy dogs. Methods: Sixteen dogs with inflammatory liver disease and 12 dogs with liver neoplasia were included in the study. Liver disease was diagnosed by clinical chemistry, ultrasonography, and histology of liver biopsy specimens. L‐Carnitine concentration was measured in plasma samples using mass spectrometry, and compared among groups using unpaired Student's t‐tests. Results: Compared with healthy controls (24.4 ± 8.4 μmol/L), the plasma L‐carnitine concentration in dogs with liver disease (44.2 ± 23.7 μmol/L) was significantly higher (P < .0001). The difference in L‐carnitine concentration between dogs with moderate (n = 8; 33.6 ± 13.7 μmol/L) and severe (n = 8; 57.4 ± 22.9 μmol/L) hepatitis was also significant (P= .02). No difference in plasma L‐carnitine concentration was found between dogs with hepatitis and those with liver tumors. Conclusions: Liver disease in dogs was accompanied by elevated plasma L‐carnitine concentration. The severity of hepatitis appears to influence L‐carnitine concentration.