UTI in a boxer puppy

Question
My 4 month old boxer/bull mastiff mix puppy is having frequent UTI. This is her second one in less than 2 months, is there any way I can prevent this?

Answer
I once had the same thing with a Lab.  My vet put her on Science C/D and that was her last infection.  I am not sure your vet will be interested in my experience.  You might find a non prescription diet to lower the urine pH like the Science C/D.  Just be careful of diet advice, the net is full of kooks pushing untested diets that can kill a dog, including experts here.