On a rotational diet, if your dog is used to rotating, you often don’t has to transition, you can switch cold turkey. But start by transitioning, until the foods you feed don’t give diarrhea, then if a food gives diarrhea or even loose stools for more than a couple days, you know it is not for your dog. When you are just starting, canned pure pumpkin, digestive enzymes, and probiotics help make transitioning easier. When I first started, I took a month to transition because I had a dog with a sensitive stomach. But after about 3 transitions, I started switching faster and faster. Now I don’t have any problems just switching up her food every day.
Try to stay with foods that are at least close in quality like 4 and 5 star foods, or 3 and 4 star foods. It’s big jumps in protein and fat levels that cause a lot of intestinal upsets, so get used to looking at the guaranteed analysis and knowing about what fat and protein level your dog is used to.
BTW, I feed kibble, canned, fresh, dehydrated, and raw, so no you don’t need to stick to one type, but you may have to pay more attention to how much water your dog is drinking if you switch between dry foods and water inclusive foods, so I usually mix the 2 together or feed them both in the same day but at different meals.
