Itchy skin or an upset stomach can both be a sign that something in your dog’s food doesn’t agree with them – but how do you know which type of specialist diet will help them feel 100% again?
In this article, I’ll explain the difference between hypoallergenic diets (for dogs with food allergies and intolerances) and gastrointestinal diets (for dogs who need a special diet to support their digestive system). I’ll cover how both these diets work, and how they can help different dogs. This blog post will also help you decide how to choose the right diet for your dog, with guidance from your vet.
Finding the best diet for your dog is really important for their comfort and health. So if you suspect your dog’s current food might be making them feel poorly, switching to a diet that avoids certain ingredients – or includes others – could be the difference between night and day!
Key takeaways
- Hypoallergenic food is formulated to tackle food allergies and intolerances, while gastrointestinal food helps support digestion for sensitive stomachs or dogs with GI conditions.
- Hypoallergenic food works by altering proteins in food, which are the ingredients most likely to cause allergic reactions.
- Gastrointestinal food works by including ingredients that support healthy digestion, and are often easy on the stomach.
- Dog food can be both hypoallergenic and gastrointestinal, to help support dogs with allergies or intolerances in addition to digestive issues or a GI condition.
- When changing your dog’s diet, make sure you switch their food gradually so they don’t refuse their food or get an upset stomach.
Table of contents
What is hypoallergenic dog food?
What is gastrointestinal (GI) dog food?
Hypoallergenic vs gastrointestinal dog food: the key differences
Types of gastrointestinal dog food explained
Why some dogs need hypoallergenic diets (immune-related issues)
Why other dogs need gastrointestinal diets (digestive-related issues)
Can a dog need both hypoallergenic and gastrointestinal food?
How to choose the right diet for your dog
How to transition between diets safely
Choosing with confidence
What is hypoallergenic dog food?
Hypoallergenic diets are formulated for dogs with allergies and food intolerances, so this type of food typically avoids the most common allergens. For example, our hypoallergenic food doesn’t include beef, eggs, dairy, soya or wheat. Hypoallergenic diets tend to fall into one of the following categories:
- Novel proteins your dog is less likely to have developed a reaction to such as rabbit, or proteins your dog has never eaten before. For example, if your dog is usually fed on chicken, you could try lamb or salmon.
- Hydrolysed diets in which the protein has been broken down into tiny pieces so as not to trigger an immune response.
- Limited ingredient diets that contain fewer potential allergens.
These diets can help dogs with allergies, as well as dogs with non-allergic food sensitivities. Here are some of the signs to look out for that could suggest your pup might benefit from a hypoallergenic diet, although you should always speak to your vet first before switching foods.
- Itchy skin, which could cause them to lick their paws more often
- Ear infections
- Skin inflammation
- Chronic soft stools or vomiting
What is gastrointestinal (GI) dog food?
Gastrointestinal diets are made for dogs who have problems with their digestive system, whether they have a diagnosed condition or a very sensitive stomach. This food is formulated to support digestion, nutrient absorption and gut recovery – it’s typically highly digestible and easy on the stomach. It might have gut-friendly fibres added like beet pulp, as well as prebiotics to help support your pup’s gut microbiome – our sensitive stomach blends use these ingredients!
Some GI foods have a high calorie content so that dogs can get all the energy they need from a meal that’s technically “smaller”, making it easier to digest. On the other hand, some diets are low in fat for dogs that have difficulty breaking down these compounds.
This type of diet is often given to dogs who have sensitive stomachs, pancreatitis or IBS – as well as dogs who have recently been unwell and need food that’s gentle on the stomach while they recover. If your dog has a combination of the following symptoms, speak to your vet and they might recommend a gastrointestinal diet.
- Reduced appetite [1]
- Frequent diarrhoea
- Vomiting
- Gas or bloating
- Weight loss
- Poor stool quality
Hypoallergenic vs gastrointestinal dog food: the key differences
So the big question is, what’s the difference between hypoallergenic and gastrointestinal food? They’re both formulated to help dogs who need a specialist diet, but they’re not exactly the same.
Hypoallergenic dog food tends to target the immune system to help dogs with food allergies. It can also be a great option for dogs with food sensitivities that don’t involve the immune system, such as lactose intolerance. Gastrointestinal diets, on the other hand, target the digestive system, making them perfect for dogs who have stomach or intestinal issues.
So while hypoallergenic diets focus on removing proteins that can cause allergies, gastrointestinal dog food is all about reducing digestive workload – making it easy for dogs to absorb all the nutrients they need without getting an upset stomach. Of course, some dogs will benefit from a diet that’s both hypoallergenic and GI, if they have allergies and intolerances as well as a sensitive stomach or digestive issues.
Comparison table: hypoallergenic vs gastrointestinal dog food
| Feature | Hypoallergenic diets | Gastrointestinal (GI) diets |
| Primary purpose | Reduce immune reactions to allergens | Support digestive health and gut recovery |
| Best for… | Skin allergies, chronic itching, ear infections, immune-mediated food allergies | Diarrhoea, vomiting, IBS and sensitive stomachs – low-fat GI diets can also help dogs with pancreatitis |
| Protein type | Novel, limited ingredient, or hydrolysed | Highly digestible (often chicken, salmon, turkey) |
| Includes grains? | May include grains (not grain-free by definition) | Often include rice or other gentle carbs |
| How it works | Reduces chance of allergic reaction or immune system response | Reduces digestive workload and supports gut lining |
| Typical duration | 6–10 week allergy trials, or long-term for dogs with severe allergies | Short-term recovery or long-term sensitive stomach support |
Types of gastrointestinal dog food explained
As we’ve briefly discussed, there are a few different types of GI dog food – here’s a breakdown of how each type is formulated to help with specific digestive issues.
Low-fat gastrointestinal dog food
- Pancreatitis: Pancreatitis can be acute, requiring short term treatment, or chronic. If your dog has been diagnosed with chronic pancreatitis, your vet might recommend that they stay on a low-fat GI diet to help prevent painful flare ups.
- Chronic diarrhoea: Chronic diarrhoea can be a symptom of several different gastrointestinal disorders. [2] Fat can increase the amount of time food stays in the system for, so a low-fat diet can be great for healthy gastric emptying, which may help to firm-up stools. However, individual responses to a low-fat diet can vary.
Fat intolerance: If your dog’s unable to digest fat easily or comfortably, perhaps due to a malabsorption issue, switching to a low-fat GI diet could really help them.
High-fibre GI diets
- Colitis: Colitis is usually a one-off but it can be chronic in some dogs. [3] Some dogs with chronic colitis might benefit from a high-fibre GI diet to help support healthy digestion – however, always consult your vet, as some dogs with colitis need a low-fibre diet instead.
- Large bowel diarrhoea: A diet that’s high in fibre as well as gentle on the stomach can really help dogs with the soft stools and frequent, urgent need to poo that comes with idiopathic large bowel diarrhoea.
- Stool quality: Adding more fibre can help make dogs’ digestive system more regular, as well as helping firm up stools.
Wet vs dry gastrointestinal dog food
Gastrointestinal dog food can be wet or dry – either wet, dry or a combination of the two would be a great option for your pup with a sensitive stomach or digestive issues.
One potential advantage of dry food is that, being more calorie dense, dogs don’t need to eat as much of it to get their nutrients. This means it might be suitable for dogs with a reduced appetite, as well as reducing the chance that their sensitive digestive system is overwhelmed.
On the other hand, wet food’s higher moisture content may improve digestibility and help replace water lost from an upset stomach. Some dogs also find wet food more palatable, meaning wet food could encourage them to eat – however, you can always add a little water to your dog’s dry food to wake up the flavours!
Why some dogs need hypoallergenic diets (allergy-related issues)
Although some dogs benefit from a hypoallergenic diet because of food sensitivities like lactose intolerance, in many cases they need this diet because they have allergies that affect the immune system. [4]
When a dog with food allergies is exposed to an ingredient they’re allergic to, their immune system treats it as a threat, which is what causes the symptoms. As well as symptoms that affect the digestive system like an upset stomach, it’s also important to look out for itchy skin, which can also be signs of a food allergy, and might even be more common. Our Head Vet Sean explains:
“If you’re wondering why your dog’s food allergy affects their skin, the answer is in part because the immune system reacts to an allergen by producing antibodies. These antibodies travel to a type of cell called mast cells (many of which are located in the skin), triggering them to release inflammatory chemicals like histamine – causing itching and swelling.”
Proteins tend to cause allergies, and common proteins are the most likely of all to trigger an allergic reaction. This is because the immune system develops its response to these proteins over time, after repeated exposure – so that’s why many hypoallergenic foods use novel proteins your dog’s unlikely to have tried before. Hydrolysed dog food breaks down the protein into such tiny pieces that the immune system won’t recognise it.
If you’re concerned that your dog might have food allergies, your vet can help you find out. As part of this process, vets often recommend an elimination diet in which you give your dog only one type of hypoallergenic food at first. Then, you can gradually reintroduce other ingredients, to help you find out what to avoid in the future.
Why other dogs need gastrointestinal diets (digestive-related issues)
Some dogs need a diet that’s formulated to support their digestive system, whether they’re been diagnosed with a GI disease or have a sensitive stomach. “Sensitive stomach” just means that your dog is prone to some digestive issues, which could of course be an undiagnosed disorder. On the other hand, a diagnosed condition, like IBS, IBD, colitis or pancreatitis has identifiable causes. Once the vet issues a diagnosis, they can give targeted advice on how to keep your dog who’s living with a GI condition healthy and happy.
GI food is also often formulated to be highly digestible, meaning that it’s easy for your dog to absorb all the nutrients they need. These types of foods can help treat diarrhoea and vomiting, because they don’t irritate the stomach lining.
If your dog has recently had an upset stomach, home-cooked foods like boiled chicken and rice can help in the short-term, [5] but unlike commercially prepared GI food, this won’t be nutritionally complete. This means it’s not suitable for a long-term diet for a dog with chronic or recurring digestive problems. If you’re looking for a long-term GI diet for your dog, look for one that’s clearly labelled “complete and balanced” – this means it has all the nutrients they need.
Prebiotics can be a wonderful addition to a GI diet, but in fact, here at Tails.com we add them to all our blends because all dogs can benefit from them. Unlike probiotics (actual living bacteria), prebiotics are a type of fibre that help those healthy bacteria grow. Prebiotics can also come in the form of fibre, fermented foods or supplements.
Fibre is itself an important aspect of a gastrointestinal diet. While some dogs need a high-fibre diet, others will benefit from a low-fibre diet. High-fibre diets can help contribute to healthy stools, but a low-fibre diet (also known as low-residue) may be more suitable for dogs with intestinal disorders. This is because less fibre means food will be digested faster, putting less strain on their digestive system.
Some GI diets are low-fat, which often helps dogs who have pancreatitis, a gastrointestinal condition that causes painful inflammation in the pancreas. Symptoms can include abdominal pain, vomiting and losing their appetite. Pancreatitis flare-ups can be triggered by eating high-fat foods, so vets often recommend that dogs with this condition follow a special diet.
Can a dog need both hypoallergenic and gastrointestinal food?
Food that’s both hypoallergenic and gastrointestinal can be just what some dogs need. For instance, dogs with inflammatory bowel disease (IBD) often have very sensitive stomachs, and while they’re not necessarily allergic to certain ingredients, exposure to them can cause an adverse response. So a diet that’s both extremely unlikely to cause a reaction – as well as highly digestible and gentle on the stomach – can be life-changing!
Highly digestible diets that use hydrolysed protein may be especially helpful for dogs with IBD. [6] However, they’re not the only dogs who might benefit from this type of diet – sometimes food allergies can cause gastrointestinal symptoms, meaning that food that’s formulated to tackle both these issues might be needed.
Remember, while both these diets include special ingredients for dogs who need a slightly different diet, they don’t always cross over. For instance, a GI diet might not automatically be hypoallergenic – it might include easily digestible chicken, which is a common allergen. And a hypoallergenic diet might not be classed as gastrointestinal if it doesn’t use ingredients that target digestive issues.
How to choose the right diet for your dog
Here’s a simple framework to help you identify the best diet for your dog, with your vet’s support.
Choose a hypoallergenic diet if your dog has…
- Itchy skin
- Recurrent ear infections
- Seasonal or year-round allergies
- Food-triggered flare-ups
- GI issues combined with skin symptoms
Choose a GI diet if your dog has…
- Sudden or chronic diarrhoea
- Vomiting
- Pancreatitis (in this case, it should also be a low-fat diet)
- IBS (IBD, however, may require a blended GI and hypoallergenic diet)
- Poor stool quality
How to transition between diets safely
If you and your vet decide a GI or hypoallergenic diet could help your dog, the first step is choosing the right new food. Then, it’s time to gently transition your pup onto their new diet. While in most cases we say the process should take 5-7 days, if your dog has a sensitive stomach, it should take longer as you’ll need to be extra careful.
Over the course of the number of days agreed on by you and your vet, gradually add a little more of the new food to your dog’s bowl every day. For instance, on Day 1 you might mix together 10% of the new food and 90% of the old food. Make sure that you’re consistent, as if you make any sudden changes to your dog’s diet, it could give them an upset stomach.
As your dog gradually moves onto their new diet, whether it’s hypoallergenic, gastrointestinal or both, there are a few things to look out for. Itchy skin, behavioural changes or unhealthy poos might all be a sign that this food doesn’t agree with your dog.
If you’re giving your dog hypoallergenic food as part of an elimination diet, make sure that you don’t give your dog any other food during this period, unless it’s a new ingredient you’re carefully reintroducing. An elimination diet or exclusion diet might last for 6-10 weeks as you identify your dog’s allergens and intolerances.
Choosing with confidence
I hope this article has helped clear up the differences between hypoallergenic diets (which help tackle allergies and intolerances) and GI diets (which help aid digestion). Some dogs with certain symptoms might benefit from a food that’s both gastrointestinal and hypoallergenic. If you’re worried about your dog who’s been showing any of the symptoms mentioned here, your vet will be able to give you helpful advice on how to care for them – and choosing the right food’s likely to be a big part of that.
If your dog has allergies or a sensitive stomach, our nutrition team can help create a tailored kibble blend that avoids their triggers and supports their overall wellbeing.
FAQs
Is gastrointestinal dog food the same as hypoallergenic?
Not necessarily, as gastrointestinal dog food is formulated to help dogs with digestive issues, while hypoallergenic food tackles food allergies and intolerances.
Can dogs stay on gastrointestinal food long-term?
Yes, gastrointestinal dog food is safe for dogs to eat long-term. Some dogs may need to stay on this type of diet their whole lives due to chronic health conditions.
Is hydrolysed dog food hypoallergenic or gastrointestinal?
Hydrolysed dog food uses proteins broken down into small enough pieces that they won’t trigger an immune response, so it’s hypoallergenic. However, it can also be gastrointestinal if it contains ingredients to support the digestive system and is easy on the stomach.
Can I feed gastrointestinal dog food to a dog without stomach issues?
Yes, any dog food that is labelled complete and balanced will be safe for a healthy dog without any digestive issues.
Sources
[1] ‘My dog isn’t eating properly’, PDSA
[2] ‘Dog diarrhoea’, PDSA
[3] ‘Colitis in dogs’, PDSA
[4] ‘Food allergies in dogs’, PDSA
[5] ‘Bland diet for dogs and cats’, Blue Cross
[6] ‘Dietary trial using a commercial hypoallergenic diet containing hydrolyzed protein for dogs with inflammatory bowel disease’, Journal of Veterinary Pharmacology and Therapeutics, 2002