What dog food is good to help with brown spots in my lawn

What dog food should I feed my dog to keep him from killing my grass

It's not the dog food. All urine contains urea i.e ammonia which converts to nitrates and an oversupply of nitrates will burn the grass just like too much fertilizer.

Heavier concentrations makes it worse. If you can take your dog out more often and spread it out that will help. Try to get the dog to drink as much water as possible.

Keep a can of water nearby and soak the area where your dog pees immediately after. Don't put fertilizer on the area, you're adding more nitrates. I have also heard that putting sugar on the grass will neutralize the ammonia but haven't tried it.

Anything you can do to dilute the urine will help.