Not many people realize animals have feelings => they get depressed too.
I would advise against overcooking meats - their instinct is still that of a hunter i.e. raw meat.
Also, I would advise against feeding them too many carbohydrates - like feeding hotdogs to a horse
Make sure their water bowl is Always full and fresh, not "any older than 8 hrs. old.
It's like drinking from last night's glass
Splitting their food into two or three smaller meals may also help.
I once had a dog when I was still in school, but that's... 35 years ago...