Difference in urinary N-acetyl-beta-D-glucosaminidase activity between male and female beagle dogs

Urinary N-acetyl-beta-D-glucosaminidase (NAG) activity differed greatly between male and female beagle dogs in an age-matched group. The NAG activity in males per animal, per body weight, or per 16-hour urine sample was approximately double that in females and was 2.4-fold higher when the activity was considered relative to urinary creatinine. On the other hand, alanine aminopeptidase activity relative to urinary creatinine was not significantly different between males and females. These findings indicate that when using urinary NAG activity to detect drug nephrotoxicity in dogs, some consideration must be given to different control levels between males and females before starting drug administration.