i'm prefer dry food for shihtzu, cause shihtzu had a long hair. dog food it's depends to your dog, you can try :science diet, regal,eagle pack,etc.can i know how old is your dog?if he under 1 year, u can give him dog food for puppy.
There are many good foods out there even on a budget it doesn't have to be something that is grossly expensive. You do want to feed dry food though, canned food is good for sick dogs, adding weight, puppies that are being weaned and seniors or dogs with no teeth. Never feed them people food this can cause pancreatitis
I give my shih tzu/poodle mixes Taste of the Wild. It's one of the least expensive grain free foods out there and it's suitable for all life stages. Their coats are shiny, they don't have itchy skin or ears and no more tear stains.
I would recommend that you get a bag of small breed dog food that has at least 30% protein and 18% fat and does not list any grain (corn, wheat, rice, and such) as the first ingredient because it will not have enough protein for your dog. I am currently feeding my dog Instinct by Nature's Variety because it is really high in protein. Although the price is quite high but I have 2 Yorkies, they only eat about 3 spoons. So it lasts a while for me. Check with Dog Food Analysis site for more info about dog food.
I keep my dogs on Natures Recipe from petsmart.I also give my dogs Just Because For Dogs treats. I like to keep the weight down and these have been the best ones that I have found. Very Healthy. You can find them at a local pet shop (not a chain) or on the internet. JUSTBECAUSEFORDOGS,COM.