Food Allergies in Pets: Symptoms and Treatment

Food allergies in dogs and cats can cause a lot of discomfort, which is why it’s important to discover the source of the problem as soon as possible. Here’s a guide to the signs and symptoms of food allergies in dogs and cats, common causes and how to treat them with the help of your local Greencross Vets team.

What is a food allergy?

Food allergies occur when the pet’s immune system overreacts to foods, usually proteins or complex carbohydrates resulting in, most commonly, itchy skin, or gastrointestinal upset such as vomiting and diarrhoea. Food allergies usually develop after prolonged exposure to one brand, type, or form of food.

How common are food reactions in dogs and cats?

Food reactions are responsible for approximately 10-15% of all allergic skin diseases in dogs and cats. For dogs, food allergies are the third most common cause of itchy skin, and they are the second most common cause of itchy skin in cats. That said, it’s far more likely for environmental allergens to trigger reactions in your pets, but ruling out food allergies will be a vital step in keeping them as healthy and comfortable as possible.

What are the signs and symptoms of food allergies in pets?

Food allergy symptoms in dogs and cats are similar to those of allergies caused by their environment, seasonal variations, and flea bites. If you notice the following symptoms, it’s worth booking an appointment with your local Greencross Vets for a diagnosis:

• Itchiness and constant scratching anywhere on the body
• Inflamed and/or dry skin
• Feet licking
• Ear infections – particularly yeast infections
• Dandruff
• Oily skin and coat
• Excessive self-grooming
• Hot spots
• Hair loss
• Watery or red eyes
• Vomiting and/or diarrhoea
• Excessive gas or flatulence

Common dog and cat food allergies and intolerances

Proteins are the usual cause of food allergies in both cats and dogs, but they can impact each species differently. Common food allergens for dogs include beef, chicken, dairy products, egg and soy. Common cat food allergies include beef, fish and chicken.

How do we diagnose food allergies in pets?

If your vet suspects a food allergy or intolerance, they’ll likely recommend a food elimination trial, as this is the definitive test for food allergies. This involves restricting your pet’s diet to a ‘novel’ protein and carbohydrate source. Novel proteins and carbohydrates as those that your pet hasn’t previously eaten.  Your pet will remain eating this exclusively for 12 weeks – they can’t be given any treats and must be restricted from any other foods they may encounter outside. 

If your pet has a food allergy, we would anticipate their gastrointestinal signs resolving within four weeks, and the skin signs after eight weeks, although we need to continue for the full 12 weeks. This approach to diagnosis must always be conducted under the supervision of your vet, as they will be able to provide specific guidance tailored to your pet’s health and nutritional needs.

Your veterinarian will be able to advise you suitable diets to offer during the elimination diet trial. These may include Hills Prescription Diet Z/D, Royal Canin Anallergic, Prime 100 Crocodile and Tapioca dog roll or another specialised diet.

Treating food allergies in dogs and cats

If your pet has responded well to the elimination trial, you may elect to continue with your elimination diet indefinitely, or your vet may recommend that we ‘challenge’ with various protein sources (eg. chicken, beef) or the original diet to determine which foods are problematic. With this knowledge confirmed, you can avoid future reactions by avoiding all foods and treats containing the trigger. And, for long-term management, you may isolate your pet’s diet to the specific pet food recommended by your local Greencross Vets team.

For further guidance around your pet’s diet or health concerns, don’t hesitate to reach out to your local Greencross Vets team.