Changing your dog’s food: how to do it right step by step

What does changing a dog’s food mean?

A food transition is the change from one food to another, whether it is a new dry food, a different manufacturer, a new life-stage food, or a change in feeding method (for example, from dry food to wet food or raw feeding). A proper food transition takes place gradually over seven to ten days so that the digestive system and the gut microbiome can adapt.

Rapid changes are the most common cause of acute diarrhea, soft stool, and flatulence in otherwise healthy dogs. The reason is not the food itself, but the microbiome: the intestinal flora is optimized for the previous food. An abrupt change creates dysbiosis, in which beneficial bacteria decrease and opportunistic microbes multiply.

Background and scientific classification

Suchodolski (2016) is considered a key reference text on the canine gut microbiome. His work shows that the dog’s gastrointestinal microbiome is a highly complex ecosystem that is adapted to specific substrates (proteins, fats, fibers). A sudden change in substrate has been shown to shift bacterial populations, with symptoms such as soft stool, flatulence, and occasional vomiting.

AlShawaqfeh et al. (2017) developed the dysbiosis index for dogs, which quantifies microbial imbalance. It shows that rapid food changes worsen the index for several days to weeks. Depending on the dog and the food, recovery time ranges from one week to several months.

Honneffer et al. (2014) demonstrated that a gradual transition over seven to ten days significantly reduces dysbiosis. The recommendation for a gradual transition is therefore not traditional, but scientifically supported.

Vitomalia position

We recommend every food transition be carried out gradually over at least seven days, and over ten to 14 days for sensitive dogs. We consider an abrupt change unnecessarily risky—except in cases of acute medical indication, where veterinary instructions take priority.

We expressly recommend not changing food during stressful phases: moving house, a new puppy phase, veterinary visits, or travel are unfavorable times. stress also affects gastrointestinal function and the microbiome.

When does changing a dog’s food become relevant?

A transition is useful in the following cases: changes in life stage (puppy to adult, adult to senior), after neutering with changed nutritional requirements, in cases of diagnosed food intolerance (see food intolerance), with chronic diseases that change dietary needs, when switching to diet or therapeutic food, and when there are quality issues with the current food. Not every change is necessary: if the current food is well tolerated and nutritionally appropriate, stability is usually the better choice.

Practical application

1. Day 1 to 2: 75 percent old food, 25 percent new food, well mixed.
2. Day 3 to 4: 50 to 50.
3. Day 5 to 6: 25 percent old food, 75 percent new food.
4. Day 7 and beyond: 100 percent new food.
5. For sensitive dogs: Extend the transition to ten to 14 days and adjust in 10 percent steps.
6. Observation: Document stool consistency, appetite, energy, and skin condition. If stools remain soft for more than 48 hours, take one step back.
7. Water intake: When switching from wet to dry food, consistently ensure sufficient water intake.

Common mistakes and myths

• "High-quality food does not need a transition." Incorrect. High-quality foods also have different substrate profiles. The microbiome needs to adapt.
• "If the diarrhea is over, the transition was successful." Visible diarrhea is only the tip of the iceberg. Subclinical dysbiosis can persist.
• "Three days are enough for the changeover." The evidence clearly supports seven to ten days.
• "Probiotics replace a gradual transition." They can provide support, but they do not replace the transition.
• "Changing food regularly makes a dog less susceptible." Frequent changes without an adjustment period increase stress load and the risk of dysbiosis. Variety only works when there is time to adapt.

Scientific status 2026

Consensus: A gradual food transition over seven to ten days is evidence-based. Research on the microbiome (Suchodolski 2016, AlShawaqfeh 2017) is becoming increasingly robust. Initial studies on prebiotics and probiotics during the transition show positive effects, but they are not yet universally recommended. Open questions: optimal transition periods for BARF and raw feeding, as well as individual variability in microbiome resilience.

Frequently asked questions

How long does a food transition take?

Seven to ten days is standard. For sensitive dogs, ten to 14 days.

What should I do if diarrhea occurs during the transition?

Take one step back and increase more slowly. If diarrhea lasts longer than 48 hours, if there is blood in the stool, or if your dog’s general condition is poor, seek veterinary advice.

Can I combine dry and wet food?

Yes, provided both are introduced gradually and the daily balance is appropriate.

Should I give probiotics?

Optional. Useful for sensitive dogs or after antibiotic treatment. Not a substitute for a gradual transition.

Related terms

• Food quantity
• Food ration
• Food intolerance
• Diarrhea in dogs
• Microbiome
• Puppy feeding
• Senior dog food

Sources and further reading

1. Suchodolski, J. S. (2016). Diagnosis and interpretation of intestinal dysbiosis in dogs and cats. The Veterinary Journal, 215, 30-37.
2. AlShawaqfeh, M. K., Wajid, B., Minamoto, Y., et al. (2017). A dysbiosis index to assess microbial changes in fecal samples of dogs with chronic inflammatory enteropathy. FEMS Microbiology Ecology, 93(11).
3. Honneffer, J. B., Minamoto, Y., & Suchodolski, J. S. (2014). Microbiota alterations in acute and chronic gastrointestinal inflammation of cats and dogs. World Journal of Gastroenterology, 20(44), 16489-16497.
4. Pilla, R., & Suchodolski, J. S. (2020). The role of the canine gut microbiome and metabolome in health and gastrointestinal disease. Frontiers in Veterinary Science, 6, 498.
5. Sandri, M., Dal Monego, S., et al. (2017). Raw meat based diet influences faecal microbiome and end products of fermentation in healthy dogs. BMC Veterinary Research, 13, 65.