Why Does My Dog Get Diarrhoea Every Time I Change Their Food?

Changing your dog’s food can sometimes lead to an unexpected problem: diarrhoea.

You may switch to a new food because your dog needs a different diet, you want to try another brand, or their usual food is no longer available. Then, shortly after the change, their stools become loose.

This can sometimes be linked to the way the new food is introduced. A dog’s digestive system needs time to adjust to changes in ingredients and other nutrients. Switching your dog’s food too quickly can affect their digestion.

The good news is that a gradual food transition may help reduce the risk of digestive upset. In this blog, we will explore how to change your dog’s food and what you can do to support your dog during the transition.

Let’s begin!

What Exactly Happens When You Switch Their Food?

When your dog eats a particular diet for a long time, their digestive system gets used to it. With a sudden change in diet, their digestive system, including the gut microbiome, has to adapt to a new combination of ingredients. This may include unfamiliar nutrient levels and fat, protein, and fibre content, which can temporarily affect digestion and the consistency of their stools. Some dogs are more sensitive to these changes than others and may need more time to adapt.

However, the problem is not always the food itself. The speed of the change can also be a factor. A sudden switch may give your dog’s digestive system too little time to adjust, leading to a temporary digestive upset. This can result in soft stools, diarrhoea, gas, or changes in appetite.

Gradual Food Transition Schedule for Dogs

A gradual transition in diet is usually easier on your dog’s digestive system. Instead of replacing their old food all at once, mix increasing amounts of the new food with decreasing amounts of the old food.

A safe and simple transition can look like this:

This seven-day schedule is a general guide. Some dogs may need a slower transition, especially if they have a sensitive stomach or have reacted badly to food changes before.

If your dog develops loose stools during the transition, consider slowing down the transition process. Stay at the current ratio for a little longer before increasing the amount of new food. Contact your veterinarian if the diarrhoea persists, worsens, or is accompanied by other symptoms.

What Can You Do to Support the Transition?

Here are some measures you can take to support your canine companion during the food transition.

Follow the feeding guide.

When switching diets, stick to the feeding amounts provided for the new food. Overfeeding can also contribute to loose stools. Different foods can have different calorie densities, so adjust the portion sizes as needed to meet your dog’s nutritional needs. Also, don’t just layer the new food; mix it thoroughly.

Keep them hydrated.

 Dogs can suffer from fluid loss due to diarrhoea. Make sure they have access to fresh, clean water throughout the day to keep them hydrated.

Change only one thing at a time.

During the transition, let their diet be the only change. Keep your dog’s routine for walking, treats, and feeding times exactly the same to avoid extra stress. You can also skip treats if needed to simplify their diet. Furthermore, avoid sudden table scraps or other dietary changes, as they may further upset the stomach.

Provide additional digestive care support if required.

You can consult your veterinarian to recommend digestive support supplements during a food transition. Probiotic products such as Pro Plan FortiFlora, Protexin Pro-Kolin+ or ZamiPet Probiotics + Gut Protect Oral Powder maybe considered as part of a broader approach to support digestive care.

When is it More Than a Transition Upset?

Diarrhoea during food transition does not always mean the new food is the problem. Dogs can develop diarrhoea for many reasons. Here are some possible causes:

• Eating something unusual: Dogs often eat things they should not, such as table scraps, rubbish, spoiled food, or unfamiliar treats. These can upset the digestive system.
• Food intolerance: Some dogs may not tolerate certain ingredients well. This can lead to recurring loose stools or other digestive problems.
• Food allergies: An immune reaction to a food ingredient can sometimes cause digestive issues.  Food allergies may also be accompanied by itching or skin problems.
• Parasites: Intestinal parasites such as worms can cause diarrhoea and other digestive issues.
• Infections: Certain bacterial or viral infections can affect the digestive tract and cause sudden diarrhoea.
• Stress: Changes in routine, travel, vet visits, or other stressful events can sometimes affect a dog's digestion and cause diarrhoea.
• Underlying health problems: Ongoing diarrhoea can sometimes be linked to underlying conditions affecting the digestive system or other parts of the body.

If diarrhoea is severe or persists for more than 24 hours, speak to your veterinarian. Seek prompt veterinary advice if your dog also has vomiting, weakness, loss of appetite, abdominal pain or blood in their stool.

Parting Words

Changing your dog's food does not have to mean dealing with diarrhoea. A gradual transition can help reduce the risk of digestive upset.

Most importantly, don't assume every episode of diarrhoea is simply caused by changing food. If you notice the problem is persistent or accompanied by other symptoms, consult your veterinarian.

A little patience during a food transition can go a long way towards helping your dog settle into their new diet comfortably.