Is it safe to feed my dog cranberry supplements to balance out his urine pH?

Q: I think my dog’s urine is becoming too alkaline due to his long term diet of Canine U/D, prescribed to prevent calcium oxalate stones to recur.  He’s been getting UTI’s over and over again despite being on antibiotics twice.  Is it safe to feed him cranberry supplements to balance out his urine pH while he’s on the U/D diet?

A: Urine problems in dogs can be frustrating, so I understand your desire to find a solution beyond the care that has already been provided for your pet. Here is what we know. Cranberry supplements may or may not lower urine PH. This has not been a consistent finding in the species that have been studied. In any case, the recurring urinary tract infections are not likely due to the Canine U/D diet. The next urinary tract infection needs to be evaluated by urine culture to determine that best antibiotic available for that particular infection and there needs to be follow-up care to assure that the antibiotic is completely effective at eliminating the infection. In addition, tests to determine the underlying cause of the recurring urinary tract infections need to be considered.