Nutrition guide
Switching dog food without a bad week
A sudden change is the most common cause of a miserable week — for the dog and the carpet. Seven days of mixing prevents almost all of it.
Why switching fast causes problems
A dog's gut is a ecosystem, not a pipe. The bacteria that digest one food are not the same bacteria that digest another, and a sudden change gives the population no time to adjust. The result is usually loose stool within 48 hours, sometimes vomiting, and occasionally a dog that decides the new food is suspicious and refuses it entirely.
A seven-day transition solves both problems. It gives the microbiome time to shift and gives you a clear signal about whether the new food suits your dog. The schedule below is the standard veterinary recommendation.
The seven-day transition
| Stage | New food | Old food | What to watch |
|---|---|---|---|
| Days 1–2 | 25% | 75% | Watch the stool. Slightly softer is normal; liquid is not. |
| Days 3–4 | 50% | 50% | Slow down here if the stool has not firmed up. |
| Days 5–6 | 75% | 25% | Most dogs are stable by this point. |
| Day 7+ | 100% | 0% | Hold for a week before judging the food itself. |
For a dog with a sensitive stomach, stretch the schedule to ten or fourteen days. There is no prize for speed, and a slower transition is almost always the cheaper option once you factor in the carpet cleaning.
How much to feed on the new food
Do not assume the same scoop size. Calories per gram vary by 20–30% between brands, and significantly more between dry and wet food. Compare the kilocalorie content on both labels and calculate the new daily amount from the calorie target, not from the old scoop.
If the old food provided 350 kcal per 100 g and the new one provides 400 kcal per 100 g, feeding the same weight gives your dog 14% more calories. Over a month, that is a visible change in waistline. Use the calculator for the daily target, then divide by the food's calorie density.
When the transition goes wrong
- Soft stool but normal energy: slow down. Hold at the current ratio for three or four extra days.
- Liquid diarrhoea, vomiting or lethargy: stop and go back to the previous food. If it continues for more than 24 hours, call a vet.
- Refusing the new food: do not starve the dog into compliance. Warm the food slightly, or mix a small amount of a safe topper such as plain cooked chicken.
- Itching or ear redness: this is not a transition problem. It suggests an allergy to an ingredient, and the food should be changed again.
Choosing the new food
Look for three things on the label, in this order:
- A statement of nutritional adequacy. "Complete and balanced" for the correct life stage, following AAFCO or FEDIAF guidelines. This is the single most important line on the packet.
- A named animal protein first. "Chicken" rather than "meat and animal derivatives".
- A manufacturer who employs board-certified veterinary nutritionists. Usually stated on the website, not the bag.
Ignore the marketing. "Holistic", "natural", "human-grade" and "premium" are not regulated terms and tell you nothing about nutritional adequacy. Grain-free is not inherently better and has been associated with a heart condition in some dogs.
If you add a supplement, a new treat and a new food in the same week, you will not know which one caused the problem. Change one variable at a time.
Coat condition, stool quality and energy take about a month to settle on a new diet. Judging a food after three days tells you about the transition, not about the food.