How to Switch Your Dog's Food Safely
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Switching foods too fast is a top cause of tummy trouble. Here's the safe, gradual way to change your dog's diet.
Why gradual matters
A sudden diet change disrupts gut bacteria and often causes diarrhea, gas, or vomiting. A slow transition lets your dog's digestive system adjust smoothly.
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The 7–10 day plan
Days 1–3: 75% old food, 25% new. Days 4–6: 50/50. Days 7–9: 25% old, 75% new. Day 10: 100% new. Slow it down further for sensitive dogs or if you notice loose stools.
Support digestion
Adding a probiotic like [FortiFlora](/products/purina-fortiflora-probiotic-supplement) during the switch helps maintain healthy gut balance and firmer stools throughout the transition.
When to slow down or stop
If your dog develops persistent diarrhea, vomiting, or refuses to eat, pause and go back to the previous ratio. If problems continue, the new food may not agree with them — check with your vet.
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Frequently asked
- How long does it take to switch dog food?
- Plan on 7 to 10 days, gradually increasing the new food. Sensitive dogs may need two weeks or more.
- Why does my dog have diarrhea after switching food?
- Usually the change was too fast. Slow the transition and consider a probiotic. If it persists, the food may not suit your dog.