Food intolerance in dogs is common but often goes unrecognised. Unlike food allergies — which involve the immune system and produce visible skin reactions — food intolerances affect digestion directly. Many owners live with a dog's intolerance for months before anyone connects the symptoms to food. Here are the signs to watch for.
the evidence
What you'll learn: The 8 most common signs of food intolerance in dogs and how to tell them from food allergies.
Table of Contents
- 1. The 8 Signs
- 2. How to Tell Intolerance from Allergy
- 3. When to See a Vet
The 8 Signs
1. Wind and bloating after meals
Excessive gas or a visibly swollen stomach after eating is one of the most common signs of food intolerance, particularly with foods the dog has difficulty digesting.
2. Loose stools or diarrhoea
Diarrhoea that happens regularly — not just occasionally after eating something unusual — is worth investigating. Chronic loose stools are not normal.
3. Vomiting after eating
Occasional vomiting can be normal. Vomiting that happens regularly, within a few hours of every meal, suggests a food-related cause.
4. Recurring ear infections
Recurring ear problems — wax build-up, redness, head shaking — often point to a dietary sensitivity. This is frequently seen with dairy intolerance.
5. Skin irritation without the classic allergy signs
Some dogs with food intolerances show mild skin irritation rather than the intense itching typical of food allergies. The skin signs are subtler.
6. Excessive paw licking
Paw licking is commonly associated with food allergies, but it also appears with food intolerances that cause low-level systemic inflammation.
7. Poor coat condition
A dull, dry, flaky coat can reflect chronic digestive inflammation from a food the dog struggles to process.
8. Weight loss without explanation
When the digestive system is not absorbing nutrients properly because of an intolerance, dogs can lose weight despite eating normally.
How to Tell Intolerance from Allergy
Food allergies typically produce skin signs — itching, hot spots, ear infections, paw licking — alongside or instead of digestive symptoms. Food intolerances primarily cause digestive symptoms: vomiting, diarrhoea, wind, and bloating.
An itchy dog with digestive symptoms is more likely to have an allergy. A dog with primarily digestive symptoms and no significant itching is more likely to have an intolerance.
Your vet can help distinguish between the two and recommend the appropriate diagnostic approach.
When to See a Vet
See your vet if your dog has any of these signs regularly — not just occasionally — and particularly if they are losing weight, seems uncomfortable, or has blood in their stool.
the evidence
This article is here to help you understand what your vet has told you. It is not a substitute for professional veterinary advice.
Last updated: April 2026
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