Urinary gamma-glutamyl transferase (GGT) as a marker of tubular proteinuria in dogs with canine leishmaniasis, using sodium dodecylsulphate (SDS) electrophoresis as a reference method

In order to assess if urinary γ- glutamyl transferase (GGT) identify tubular proteinuria in leishmaniotic dogs, the GGT/urinary creatinine (UC) ratio was calculated in 39 leishmaniotic dogs. According to sodium dodecylsulphate-agarose gel electrophoresis, the dogs had albuminuria (A, n = 10), glomerular (G, n = 3), tubular (T, n = 4) or mixed proteinuria (M, n = 22). The median GGT/UC ratio was 0.3, 0.3, 2.2, and 7.5, in groups G, A, M, and T, respectively. Statistically significant differences were found between groups G and M (P = 0.002), G and T (P < 0.001), A and M (P < 0.001), and A and T (P < 0.001). Median values were higher in dogs with tubular components of proteinuria (M/T, 2.5) than in dogs without tubular components of proteinuria (A/G, 0.3), and in dogs with tubular proteinuria (T, 7.5) than in dogs with non-tubular proteinuria (NT, 1.0). GGT/UC values >0.81 or >2.64 could identify dogs in the M/T or T groups, respectively. Therefore, GGT/UC might be useful for the management of leishmaniotic dogs.