When my dog was on an elimination diet, she started on white rice and (canned) salmon. No reaction for several days, and we added sweet potatoes and switched to brown rice. No reaction. We added tuna. Cheaper than salmon. No reaction. We allowed some soup bones she could chew on, and boiled them first, and use the broth for cooking the rice.
Then we added in this order:
red potatoes
babyfood oatmeal (in the box) for the vitamims
chopped green veggies, like spinach and broccoli
cottage cheese
brewer’s yeast (dog LOVED a bowl of chopped veggies and potatoes boiled in beef brother, mixed with cottage cheese and brewer’s yeast. She sucked it down so fast, you weren’t sure you’d actually given it to her)
peanut butter, given with trepidation, because it’s a doggie fave, but no reaction
corn.
WOW. Massive reaction. Corn was the culprit. So we found a dry food with no corn, and got that for her. She wanted her tuna and cottage cheese again, so we had no mix some into the hard food, and fade it until after two months, she was just eating the food.
I suspect if your dog had all those things, minus the corn, of course, and with the addition of some mutton or hamburger, the dog would have everything it needs. You can use low-fat cottage cheese-- we used full fat, because our dog was thin. If your dog can’t tolerate it-- ours was barely a year old, and still probably had some milk-digesting enzymes-- you could try yogurt, or look for lactose-free cottage cheese. Or add lactaid. I wouldn’t use fat-free, because the vitamins in the veggies need some fat to be absorbed correctly. Course, I suppose if you fry them in some kind of oil your dog can tolerate, you wouldn’t need any dairy at all.
You could probably use human oatmeal, not baby oatmeal flakes.
If your dog can tolerate corn, I understand it’s a good source of roughage.
Many dogs are allergic to chicken, but not turkey; however, good luck getting turkey outside of Oct-Jan.
Talk to your vet about what your dog’s needs are, and them look for the vitamins the dog needs. We had to give a phosphorus supplement in the beginning.
The dog in question that I did this for lived to be 15 1/2, which was really old for a dog her size. (70 lbs.) She would run, hike, swim, chase and wrestle with other, younger dogs right up until her last couple of weeks, and she had good eyesight; she could spot a squirrel running through the yard from out our third floor window.