In the study presented herein, we sought to clarify the effect of metabolic acidosis on the progression of acute pyelonephritis in C3H strains prone to VUR by administering ammonium chloride via supplementation of food, which induces metabolic acidosis in rodents without eliciting an AVP‐mediated dehydration response (Nowik et al., 2010). Here, AVP is linked to pyelonephritis.