Preliminary Results of Variation in Plasma N-acetyl-beta-D-glucosaminidase Concentration Among Bearded Dragons (Pogona vitticeps), Corn Snakes (Pantherophis guttatus), and Wood Turtles (Glyptemys insculpta)

Abstract

N-acetyl-beta-D-glucosaminidase (NAG) is a lysosomal enzyme found in renal tubular epithelial cells whose concentration can be measured in blood as a possible diagnostic tool to monitor renal disease; however, no reference values are currently available in reptiles. This study investigated the presence of plasma NAG concentrations in 3 reptile species. Blood samples were obtained from clinically healthy bearded dragons (Pogona vitticeps; n = 13), corn snakes (Pantherophis guttatus; n = 9) and wood turtles (Glyptemys insculpta; n = 13). To further assess renal health, a biochemistry panel was performed for all animals, and renal biopsies were collected from the bearded dragons and snakes, but not from the turtles. Biopsies were not taken from wood turtles to limit the risk associated with anesthetizing an endangered species. Of the 35 animals sampled, 29 were considered healthy and included in the study. Plasma NAG concentrations in the wood turtles were significantly lower than in the corn snakes (P = 0.004) and plasma NAG concentrations in the corn snakes were significantly higher than in bearded dragons (P = 0.038). Wood turtles had the lowest NAG concentrations, followed by bearded dragons and corn snakes. In conclusion, NAG reference intervals should be established for each reptile species and analyte validation is needed for this assay in reptiles. Further research is needed to establish NAG reliability as a diagnostic tool in reptiles.