Ammonium urate nephrolithiasis occurs in common bottlenose dolphins (Tursiops truncatus) managed under human care but not in free-ranging dolphins (Smith et al., 2013). In mammals, purine-rich diets, such as the piscivorous diet of dolphins, can predispose to urate urolith formation (Osborne et al., 1995). The total purine content of food is measured commercially by summing the concentrations of four purine...