How to switch dog food
A dog's gut gets used to one food. A sudden change often gives soft stool, gas or vomiting for a few days. So mix the new food into the old food, a little more each step:
- Days 1–2: ¾ old food, ¼ new food
- Days 3–4: half and half
- Days 5–6: ¼ old food, ¾ new food
- Day 7: all new food
Keep the total the same. Each meal is one normal portion, just made of two foods. Keep treats the same too, so you know what caused any change.
Sensitive stomach: go slower
Give each step 3 days, so the switch takes 10 days. If the poop gets soft, stay on the same step for 2 or 3 more days. If it is still soft, go back one step. Only move on when the poop is firm.
A quick check: firm, log-shaped and easy to pick up is good. A soft pile that keeps its shape is OK for a day or two. A puddle means go back one step.
When to stop and call a vet
- Blood in the poop, or black, tar-like poop
- Vomiting more than once, or diarrhea for more than 2 days
- Your dog will not eat, or seems tired and weak
- A puppy, a very small dog or an old dog with diarrhea for a day
Go back to the old food while you wait. A bland diet for 2 or 3 days can help: see the bland diet calculator.
Questions
Can I switch dog food without mixing?
Some dogs cope fine, but many get an upset stomach for a few days. If the old food is gone, start the new food in small meals, 3 or 4 a day, for the first days.
Do I need to mix if it's the same brand?
Yes, if the recipe is different. A new flavor or a new protein, such as lamb after chicken, can upset the stomach just like a new brand.
Wet food to dry food?
Use the same plan. Mix by portions of the day's food, not by weight: a can and a cup hold very different calories. Check both labels for the amount.
Switching for a food allergy?
An elimination trial uses one new food only, for 8 to 12 weeks, with no other treats or snacks. Plan it with your vet, so you know what you are testing.
My dog won't eat the new food. What now?
Do not add toppings yet. Offer the mix for 15 minutes, then take it away until the next meal. Most dogs eat by the next day. If your dog skips more than a day, go back to the old food.