Food allergy in cats
Also known as Adverse food reaction, Food intolerance.
An immune reaction to a protein in the diet, almost always one the cat has been eating for some time. It causes itching on the head and neck, and sometimes vomiting or diarrhoea.
- System
- Skin and coat
- Is it urgent?
- Not usually
- Spreads to other cats
- No
- Spreads to people
- No
- Typical cost in Spain
- Consultation, €40–70; hydrolysed diet, €30–70 a month.
Symptoms
- Intense itching on the face, ears and neck
- Wounds from scratching
- Recurring ear infections
- Vomiting or diarrhoea in some cats
Causes
Common dietary proteins: chicken, beef, fish and dairy are the most often cited because they are the most widely used.
How it is diagnosed
Only through a strict elimination diet of at least 8 weeks, with a hydrolysed or novel protein, followed by reintroduction. Blood and hair tests are not reliable.
Treatment
A permanent diet without the protein responsible, and itch control while it is being adjusted.
No doses, on purpose: any medicine must be prescribed by your vet for your cat.
Prognosis
Good if a diet the cat tolerates is found and stuck to.
Prevention
It cannot be prevented; relapses can be avoided by making sure the cat eats nothing else.
Breeds at higher risk
It is described more often in these breeds. That does not mean all of their cats will have it, nor that a moggy is free of it.
Frequently asked questions
Is food allergy contagious?
No. It does not spread to other cats or to people.
Can food allergy be cured?
Good if a diet the cat tolerates is found and stuck to. A permanent diet without the protein responsible, and itch control while it is being adjusted.
How much does it cost to treat food allergy?
As a guide for Spain in 2026: Consultation, €40–70; hydrolysed diet, €30–70 a month. Prices vary a lot between clinics and cities, and out-of-hours emergencies cost more.
Which breeds are most at risk?
It is described more often in Siamese. That does not mean every cat of those breeds will have it, nor that a moggy is free of it.
More in skin and coat
Educational content from Michipedia. It does not replace diagnosis or treatment by a vet: if you have any doubt about your cat's health, ask. Costs are a guide for Spain in 2026.