What’s in your Dog’s Bowl matters

Is Your Dog Trying to Tell You Something? Understanding Food Intolerances and Allergies

You know your dog. You notice when something is off — the persistent scratching, the upset stomach that seems to come from nowhere, the dull coat that no amount of brushing seems to fix. These signs are easy to dismiss as ordinary, but they may point to something worth investigating: a food intolerance or allergy.

Food-related reactions are among the more common reasons pet owners seek veterinary advice. According to a 2016 systematic review published in BMC Veterinary Research, cutaneous adverse food reactions account for approximately 1–2% of all dermatological cases in dogs, and up to 20% of cases of allergic skin disease (Verlinden et al., 2006; Mueller et al., 2016).

Intolerance vs. Allergy: Why the Distinction Matters

A true food allergy involves an immune-mediated response triggered by a specific protein antigen. Food intolerance does not involve the immune system; it may stem from enzyme deficiencies, pharmacological reactions, or metabolic issues (Day, 2005; Verlinden et al., 2006). Both can produce similar clinical signs. What matters is identifying the source.

What Causes a Reaction?

Research consistently identifies certain ingredients as more commonly implicated. A 2016 review by Mueller, Olivry, and Prélaud analysed 297 dogs across multiple studies and found beef, dairy, wheat, and chicken were the most frequently reported triggers. Lamb, soya, and egg featured less commonly but still appeared in the literature.

These are not inherently harmful ingredients — they are simply proteins to which individual dogs may develop sensitivity over time. Sensitivity can, in principle, develop to any dietary protein.

Signs to Look For

The clinical presentation is varied. Non-seasonal pruritus (itching), recurrent otitis externa (ear infections), and pododermatitis (paw licking and redness) are among the most frequently reported dermatological signs (Olivry et al., 2010; WSAVA Dermatology Guidelines, 2019). Gastrointestinal signs — vomiting, loose stools, flatulence — occur in a subset of affected dogs, sometimes alongside skin signs.

You might notice your dog:

• Scratching persistently around the face, ears, and paws

• Experiencing recurring ear infections

• Having loose or inconsistent stools

• Presenting a coat that has lost its usual condition

If these signs appear regularly and do not resolve with seasonal changes, a dietary component is worth investigating.

The Gold Standard: Dietary Elimination Trials

Current veterinary consensus — as outlined in the WSAVA Veterinary Dermatology Guidelines — is that the dietary elimination trial remains the most reliable diagnostic approach. Intradermal testing and serum allergen testing are not considered diagnostically valid for food antigens in dogs (Olivry & Mueller, 2017).

An elimination trial involves feeding a hydrolysed or novel protein diet for a minimum of eight weeks (some guidelines recommend twelve), with strict adherence: no treats, flavoured medications, or table scraps, as even small exposures can confound results. Reintroduction of suspected ingredients is the confirmatory step. A return of clinical signs following rechallenge is considered diagnostic.

This is not a process to navigate alone — veterinary guidance is strongly recommended.

What You Can Do in the Meantime

Keeping a detailed diet and symptom diary is genuinely useful. Recording what your dog eats alongside changes in stool quality, skin condition, and energy levels can reveal patterns — and gives your vet valuable information. Reviewing ingredient labels carefully is also a reasonable first step; protein sources can appear under multiple names, and beef derivatives may not be immediately obvious.

Your dog cannot tell you something feels wrong. But they show you, every day. Paying close attention to those signals — and taking them seriously — is one of the most meaningful things you can do for their long-term wellbeing.

When it comes to treats and chews, choosing single-ingredient, natural options removes a layer of complexity. Fewer ingredients means fewer variables — and a clearer picture of what your dog is and is not tolerating well.

References

Day, M.J. (2005). Immunological mechanisms of adverse reactions to food. Veterinary Dermatology, 16(4), 230–241.

Mueller, R.S., Olivry, T., & Prélaud, P. (2016). Critically appraised topic on adverse food reactions of companion animals: common food allergen sources in dogs and cats. BMC Veterinary Research, 12, 9. https://doi.org/10.1186/s12917-016-0633-8

Olivry, T., & Mueller, R.S. (2017). Is there validated evidence that hydrolysed protein diets are suitable for partial allergen avoidance? Veterinary Dermatology, 28(1), 26–e6. https://doi.org/10.1111/vde.12355

Olivry, T., & Mueller, R.S. (2018). Labelling of commercial pet foods for the management of cutaneous adverse food reactions. BMC Veterinary Research, 14, 257.

Olivry, T., DeBoer, D.J., Favrot, C., et al. (2010). Treatment of canine atopic dermatitis: 2010 clinical practice guidelines. Veterinary Dermatology, 21(3), 233–248.

Verlinden, A., Hesta, M., Millet, S., & Janssens, G.P.J. (2006). Food allergy in dogs and cats: a review. Critical Reviews in Food Science and Nutrition, 46(3), 259–273.

WSAVA Dermatology Guidelines (2019). Guidelines for the Diagnosis and Treatment of Dermatological Conditions in Dogs and Cats. wsava.org