Food transition: how long to switch kibble?

To change your dog's or cat's kibble without upsetting their digestion, generally allow 7 to 10 days of gradual transition, mixing the old and new kibble in proportions that slowly reverse. A change that is too sudden is the most common cause of temporary digestive upset when switching food.

1. Why a gradual transition helps

A dog's or cat's gut flora adapts to the composition of what they regularly eat: digestive enzymes and intestinal bacteria calibrate to the usual recipe. Switching kibble overnight asks this balance to adjust abruptly to a new composition, which is why some animals show soft stools or temporary digestive discomfort after a change that is too fast. A transition spread over several days gives the body time to adapt gently.

2. A transition schedule, for general guidance

Here is a general schedule, to be adapted to your animal's tolerance: some dogs and cats only need 5 days, others benefit from a transition spread over 2 weeks, especially animals with a sensitive digestive system.

Days	Old kibble	New kibble
Days 1-2	75%	25%
Days 3-4	50%	50%
Days 5-6	25%	75%
Day 7 onwards	0%	100%

If you notice soft stools at a given stage, it is perfectly fine to stay one or two more days at the same step before continuing, rather than following the schedule too rigidly.

3. When a transition is needed

• Changing kibble brand or range.
• Switching from puppy or kitten kibble to adult kibble.
• Switching to senior kibble.
• Changing flavour within the same range, especially for animals with a sensitive digestive system.
• Going back to a previous kibble after testing another product.

4. How to organise the change in practice

• Weigh the two kibbles separately at the start, rather than estimating proportions by eye.
• Keep the same meal times throughout the transition, so as not to add a second habit change at the same time.
• Avoid starting a transition right before a stressful event (a move, travel, the arrival of another pet) if you can plan it ahead.
• Keep a little of the old kibble aside for the first days after the transition ends, in case you want to go back.

5. Dog or cat: is there a difference?

The principle of a gradual transition is the same for dogs and cats, but cats sometimes show a stronger sensitivity to sudden changes, including in kibble texture or shape, and may turn up their nose at a bowl that seems unusual to them. For cats, it can help to slightly lengthen the transition period or mix the kibbles directly in the same bowl rather than offering two separate bowls.

6. Signs that should prompt a vet visit

Repeated vomiting, diarrhoea lasting more than two days, a total refusal to eat or prolonged loss of appetite should not automatically be blamed on the food transition: these are signs to have checked by a veterinarian, who can determine whether the cause is really linked to the food change or something else.

7. Changing formula type (grain-free or not)

Changing flavour within the same range is generally simpler than switching formula type entirely, for example moving from a classic recipe to a grain-free one. In that case, the texture, energy density and sometimes the kibble size can be quite different, which is a good reason to be even more gradual and to watch your animal's stools closely throughout the change. Our article grain-free kibble explains the main differences between these two formula types, useful reading before starting this kind of transition.

Also remember to keep enough fresh water available throughout the transition: a kibble change can slightly affect your animal's thirst, especially if the new formula does not have exactly the same moisture content as the old one.

8. Choosing the destination kibble well

A successful transition also starts with choosing the right destination kibble, suited to your animal's age, size and profile. To help with this choice, our articles how to choose your puppy's kibble, how much kibble for a dog and kibble for neutered cats cover several common profiles. You can also browse our full range of dog kibble and cat kibble.

9. In short

A successful food transition generally takes between 7 and 10 days, gradually mixing the old and new kibble. Adjust the pace to your animal's tolerance, and see a veterinarian if digestive issues persist beyond a few days. With patience and a suitable schedule, the vast majority of dogs and cats switch kibble without any particular issue, and the discomfort of the first days usually fades quickly once the new food is fully introduced.

Need help finding the destination kibble? Take our 2-minute quiz for a selection suited to your animal's profile: find the right kibble.