When Darci had a UTI Her urinary ph was at 8.5, tested at the vets office.
I work in a doctors office and brought home the strips to test her urine with.
At the time of the vet visit, they advised me to change her diet and add bottled water and cranberry.
She had 2 UTI's in a 8 month period. After making the above changes I made she hasnt had one since. It's been around 5 - 6 months aprox.
I used pool strips to check the ph of my tap water, as well as the office urinary strips.
Now Darci's urine stays around 6.5. I havent checked it though in about 6 weeks.
Since the food is in a good range for ash levels, I would do the cranberry and water changes then test the urine and see if it has fixed the problem.
Does he drink enough water ? I also add a little water to her food both am and pm feeding. ( about 1/4 - 1/3 cup of water )
The high ph levels over time can cause crystals in the bladder which can cause inflammation and lead to UTI, urinary incontinence, bloody urine (hematuria ), bladder stones etc.
We didnt know Darci had a problem until she starting wetting in the house and had hematuria ( blood in her urine ).
I am no expert by any means but these are things that worked for us, I learned alot from our vet and through some help from other dog owners on boards like this one.
I had some people suggest distilled water and some say only distilled water for no more than a week, I couldnt find a concrete answer either way so I went with bottled water.
I tested our bottled water several times and it was always around 5 or so.
As far as testing the urine, I follow her during potty breaks, and slide a plastic bowl under her when she squats, then dip the stick in her urine.
I get strange looks from the dog and my neighbors....lol
I hope this info has helped.