Your dog may have more than 1 type of stones, my dog had both struvite and calcium oxalate, there is a genetic component, some dogs have a predisposition to develop them.
I think the confusion you are having is that you are listening to homeopathic views (the nutritionist) versus the traditional veterinarian. The two will never agree. I prefer science based veterinary medicine. I would be inclined to listen to your vet and do what he recommends, prescription food and all, you can always add something to it with your vet’s approval. Once the dog is stable, you can re-evaluate diet options.
Did you check the search engine here /forums/search/struvite/
Water, water, and more water.
Frequent bathroom breaks. Otherwise, consult a Veterinary Internal Medicine Specialist.
The food can only do so much, most supplements are crap.
The PH strips are a joke, go to your vet every 3 months to check (urine sample).
Even with dietary changes, a change in the PH won’t show up for a month or two (this is what my vet told me).
Also, walk the dog more, get the extra weight off. Two meals a day, measured amounts, no snacks. No free feeding. If need be, 3 small meals per day.
PS: Nothing wrong with prescription dog food. http://skeptvet.com/Blog/2016/07/more-nonsense-from-holistic-vets-about-commercial-therapeutic-diets/
