Your vet has prescribed a new diet for your dog, you have brought the bag home — and now comes the part many pet parents get wrong: the switch itself. Changing your dog's food overnight is one of the most common causes of an upset stomach. Loose stools, gassy tummies, and a dog that turns away from the bowl are often not a problem with the new food at all, but a problem with how quickly it was introduced. A slow, planned transition protects your dog's digestion and gives the new diet a fair chance to work.
Why a sudden switch upsets the stomach
A dog's gut is home to trillions of bacteria that help digest food, and those bacteria are tuned to the food your dog has been eating. Change the food suddenly and the gut bacteria need time to adjust to the new protein, fibre, and fat levels. During that adjustment, digestion becomes less efficient, which is why loose stools and wind are so common after a sudden switch. Dogs with sensitive stomachs, puppies, and older dogs are affected most, but even a healthy adult dog can have a few unsettled days after an abrupt change.
The seven-day transition plan
- Days 1–2: mix about one quarter new food with three quarters of the old food.
- Days 3–4: move to half new food and half old food.
- Days 5–6: feed about three quarters new food and one quarter old food.
- Day 7: feed the new diet on its own.
- If stools become loose at any stage, stay at that ratio for an extra day or two before moving on.
- Keep mealtimes, the feeding bowl, and the feeding spot the same throughout the switch.
Most dogs move through this plan without any trouble. If your dog has a very sensitive stomach, your vet may suggest a slower switch over ten to fourteen days instead — that is perfectly fine. The goal is a calm gut, not a fast switch, so let your dog's stools and appetite set the pace.
If your dog refuses the new food
- Warm the food very slightly — a little warmth releases aroma and makes it more tempting.
- Add a spoonful of warm water to dry food to soften it and bring out the smell.
- Keep to the usual feeding routine, and offer the bowl for twenty minutes before taking it away.
- Do not add gravy, curd, or table food to tempt your dog without checking with your vet first.
- If your dog refuses food completely for more than a day, call your vet.
Feeding a sensitive stomach long term
For dogs whose stomachs stay sensitive, a diet formulated to support digestive health can make daily feeding much easier. Drools VET PRO Gastrointestinal Adult Dog Dry Food is a veterinary diet formulated to support dogs with digestive sensitivities, with nutrition designed to be gentle on the gut. It should only be fed on your vet's recommendation, and your vet will advise on portions and how it fits with any other care your dog receives. Alongside the right diet, regular mealtimes, measured portions, fresh water, and no table scraps give a sensitive stomach its best chance to settle.
When to call your vet
- Vomiting or diarrhoea that lasts more than two days.
- Blood in the stool or vomit, or very dark, tarry stools.
- Refusing food for more than 24 hours, or refusing water.
- Lethargy, a swollen belly, or signs of pain.
A prescription diet only works if your dog actually eats it — and eats it happily. Take the switch slowly, watch the stools, and be patient for the first week. Once the transition is done, most dogs settle into their new food and their digestion settles with it.
Drools VET PRO Gastrointestinal Adult Dog Dry Food is available at Paw Store.
It is available at Paw Store in 3kg and 8kg packs.
This article is for general information only and is not veterinary advice. Prescription diets should only be fed under veterinary supervision. Always consult your vet before changing your dog's diet, especially if your dog has a diagnosed health condition.
Shop genuine veterinary diets at Paw Store (pawstore.in) with same-day delivery in NCR and fast shipping across India.