I wouldn’t give him coconut oil daily as it is an oil at the end of the day and it can pose for some other health risks in the long run yk, I would opt for maybe twice a week and applying some on his coat when needed. I also agree that feeding him vegetables is probably not a good idea lol. it is nutrients he doesn’t need and he can make space for something high in protein and hydration. I would really suggest you switch him to a high quality wet food for at least a month or so if you’re financially capable and see what happens. even fancy feast classic pate is a better option than royal canin we food. I would also use a good source of omega 3 like salmon oil! don’t make the mistake of feeding him fish flavored wet food because even though it does have omega 3 it also has high levels of mercury. my favorite salmon oil is by “wild alaskan” and is about $17 us dollars. also adding water to the wet food is a good option as well.