Association between Increased the De Ritis Quotient and Renal Azotaemia in Canine Babesiosis

SIMPLE SUMMARY: This study investigated the association between increased serum aspartate aminotransferase (AST) activity and renal indices such as renal failure index, sodium fractional excretion, and urinary creatinine to serum creatinine ratio in dogs with renal azotaemia infected with Babesia canis. This research revealed that increased serum AST activity in azotaemic dogs may be of renal origin, and the de Ritis quotient may be a convenient and useful tool in the recognition of renal azotaemia in canine babesiosis. ABSTRACT: Previous studies of azotaemia in canine babesiosis revealed pre-renal and renal azotaemia in infected dogs, and an association between an increased de Ritis quotient (aspartate aminotransferase to alanine aminotransferase activity; AST/ALT ratio) and azotaemia in affected animals. Serum activities of AST and ALT, and AST/ALT ratio were compared between azotaemic and non-azotaemic dogs infected with Babesia canis, and between affected dogs with pre-renal and renal azotaemia. Statistical analyses revealed higher AST activity and an increased AST/ALT ratio in azotaemic dogs, and an increase of these two parameters in infected dogs with renal azotaemia in comparison to dogs with pre-renal azotaemia. Moreover, AST activity and AST/ALT ratio were correlated with renal indices such as renal failure index, sodium fractional excretion, and urinary creatinine to serum creatinine ratio. The study also revealed a lack of correlation between AST and ALT activities in azotaemic dogs, although a correlation was observed when including all dogs in this study (azotaemic and non-azotaemic dogs treated as one group). The results of this study indicate that increased serum AST activity in azotaemic dogs infected with B. canis may have a renal origin, and the AST/ALT ratio could be considered as a simple and convenient renal index that is useful in the recognition of renal azotaemia in canine babesiosis.