Transitioning Your Dog To A New Food: 
How To Switch Dog Food Brands

Unlike humans, a dog’s digestive system isn't designed to handle sudden dietary changes. Switching foods too quickly often leads to stomach upsets or an "aversion" to the new food (food aversion). While a consistent diet is usually best, changes are sometimes necessary such as moving from puppy to adult food, managing a health condition under veterinary advice, or simply switching to a new brand or recipe.

Whatever the reason, introducing a new diet must be done slowly to minimise issues like diarrhoea and ensure your dog happily accepts their new meal.

Why A Slow Transition is Recommended

Taking your time with diet changes is the best way to support your dog’s internal health. Remember: there is no such thing as too slow.

• Supports the Gut Microbiome: A gradual switch allows the "microbiome" (the community of bacteria and micro organisms supporting digestion) to adjust to new ingredients and nutrient profiles. Sudden changes can overwhelm the gut microbiome, leading to digestive upsets like loose stools, vomiting, excessive flatulence or reduced appetite. Gradually transitioning allows time for the gut microbiome to adapt, supporting digestion and reducing the risk of gastrointestinal upset.
  
• Encourages Acceptance: Gradual changeover makes the experience less stressful for the dog, helping to encourage acceptance of the new diet.
  
• Easier Monitoring: You can pause or stop the transition if you notice your dog isn't tolerating their new food.

It is a common misconception that you can swap between different formats or recipes instantly if they are from the same brand. Even when switching between Prime100 diets, it’s important to make changes gradually, including when you’re switching between formats.

While our SPD™ (Single Protein Diet) recipes all follow the same principle of using a single animal protein source, each diet has a unique formulation and a different nutrient profile on a dry matter basis. These differences can influence how a dog’s gut responds to the food. Whether you are moving from a SPD™ Fresh Roll to our SPD™ Slow Cooked range or trying a new SPD™ Air Dried protein, we still recommend introducing the new format gradually to support a smooth, comfortable transition for your dog’s digestive system.

Gradual Transition Schedule

For most dogs, a 7-10 days transition generally works well.

Day 1: Replace 25% of the old food with the new food.
Days 2–6: Gradually increase the proportion of the new food every day or so.
Day 7: You should be feeding 100% of the new diet

Need to go slower? Dogs with sensitive stomachs or picky appetites often need a slower transition. In these instances, a gradual 2–3 week transition can help reduce digestive upset and increase the acceptance of the new food.

Signs to Watch For During a Transition

Early Signs (Common during the first few days of transition)

Provided these signs remain mild and do not persist, it is fine to either slow or continue the transition.

• Stool Changes: Mild changes in consistency are normal initially. If diarrhoea persists or contains blood or mucus, contact your vet.
• Reduced Appetite: Reduced appetite is common, especially for fussy eaters! Appetite should improve gradually with time however if you feel it isn’t, it’s best to speak with your vet

Long-Term Indicators of Success

As your dog has transitioned onto their new diet, you can monitor them to see how well they have adapted. Some nutritional benefits, like improvements in skin and coat, can take up to 9 weeks to show!

• Ideal Weight: A suitable diet helps maintain a healthy body condition.
  
• The "Glow": Healthy skin and a shiny coat are often direct indicators of diet quality. Should you observe any changes in your dog's coat quality or skin health, it is advisable to consult a veterinarian to determine if their current diet is appropriate.
  
• Stable Digestion: Minimal upsets and consistent, healthy stools.

If these signs appear, pause the transition, return to the old food, and contact your veterinarian:

• Vomiting signals serious digestive upset, risking rapid dehydration and lethargy.
• Not eating at all. While a mild drop in appetite during a transition is normal, complete refusal to eat warrants veterinary advice.

To help you track your dog's progress, we have created a downloadable Food Transition Diary. Keeping a diary is a simple yet effective way to record any subtle changes in your dog’s appetite, energy, or stool consistency. By documenting these details daily, you can easily identify if the transition is moving too quickly or if a specific diet is the perfect fit for your dog

Additional Tips for a Successful Diet Transition

• Keep Routines Stable: Maintain your dog’s regular mealtimes and eating areas.
• Skip the Treats: Avoid treats, table scraps or human foods during the transition to reduce the workload on the digestive tract and minimise the chance of digestive upset. Additionally, satisfying your dog’s hunger with additional foods and treats makes it less likely for them to engage with the new diet!
• Check the Temperature: Gently warming food, especially wet food, enhances the aroma and makes it more enticing.
• Trial Period: Provided your dog is well, aim to trial a new diet for at least two months before deciding if it’s the right fit.

Special Considerations for Elimination Diets & Food Allergic Dogs

While a standard transition involves mixing old and new foods, the rules change when you are managing suspected food sensitivities or allergies. For these dogs, we recommend discussing an elimination diet trial to identify specific triggers with your veterinarian.

Why You Shouldn't Mix Foods During a Trial

During an elimination diet process (sometimes called a food trial), the effectiveness hinges on your dog eating a novel protein—a completely new protein they’ve never consumed—and a single protein diet containing only one source of animal protein.

If you mix a novel protein, such as Crocodile, with an old diet containing a protein your dog is already reacting to (like Chicken), the immune system may mistakenly develop a new allergic response to the Crocodile. This "cross-reactivity" can ruin the trial before it even begins.

The 'Dilution' Method

Instead of mixing the old and new diets, we generally recommend "diluting" the new food with a source of digestible carbohydrate to help the gut adjust without introducing old allergens. This allows your dog’s immune system to only "see" the new, novel single protein while the added carbohydrate supports digestive health during the switch.

Steamed and mashed pumpkin or cooked quinoa are generally ideal to use to “dilute” the new diet.

The added carbohydrate source can be added to your dog’s diet using the same 7-10 day transition period as used when mixing two different diets. 

How Prime100 Supports the Switch

Many of our Prime100 Single Protein Diets (SPD™) have been developed specifically to support dogs during this elimination diet period.

• Single Protein Diets: Each diet is formulated using a single source of animal protein. For those needing an alternative to animal protein, our Pea & Algae Oil SPD™ Fresh Roll uses pea protein isolate as the single protein source.
• Limited Ingredients: Each diet is crafted using a limited number of ingredients, helping to support gastrointestinal health and simplifying your dog’s diet to make trigger identification easier.