But I'm wondering what else I can do to prevent these UTI and if there is a food which I should be feeding that is better for him.
An alternative would be to change his water supply (go bottled, if you need to), and add a capful of apple cider vinegar (ACV) to his food or water daily. This would need to be "real" ACV, the natural cloudy stuff with bits of 'mother' floating in it, which you'd generally find in a health food store. NOT the nice clear scalded/sterilized-and-filtered-to-death stuff you get in grocery stores.
You should also take a look at lifestyle factors. Bladder crystals form when (a) the bladder conditions are either too acidic or alkalyne, and (b) when the urine is allowed or forced to concentrate regularly. That last point is very important. It is near impossible to develop crystals if you maintain proper hydration all of the time, and urinate regularly. In these (natural) conditions, urine remains fairly dilute, and bacteria is flushed from the body regularly via the urine - just as nature intended.
lifestyle factors that directly affect this are (a) how much and how often your dog drinks, (b) how often he has the opportunity to urinate, and (c) his diet. Sooo - how often does your dog have the opportunity to urinate? It should be every couple of hours or so, and really needs to be whilst you're battling this sort of condition (even if it's slightly less frequently on a long term basis). This dog is not a candidate for being crated or home alone for 8 hours daily. And second, do you feed anything but dry food? If not, you really should. Dry food is dehydrating (its one reason dry fed dogs usually drink large amounts - as indeed you or I would if our daily meals were dry cereal), and dehydrating is the worst thing for a dog with bladder crystals. If you can manage it, swapping to a hydrated food (canned, homecooked, raw - anything but kibble) would be very helpful. Or if you can't completely swap, then at least feeding some portion of his diet in normally hydrated food would be very helpful.
With the above, you address the most likely causes of your problem. The alternative is a simple switch to a low grade food - but (quality issues aside), you're treating symptoms rather than cause by going that route. Taking care of the cause of the problem is a better solution
and one likely to have wider health benefits.
