Dog Food Allergies

This week our Vet Alison tells us more about food allergies. A food allergy is an abnormal response to a food triggered by the dog’s immune system.

The food that the immune system recognises and reacts to is called the allergen. Allergic reactions are most commonly associated with protein sources. Most protein containing foods have the potential to induce an allergic reaction in a predisposed animal.

A dog will not be allergic to a totally new ‘novel’ protein source as it is only after repeated exposure that the misguided immune system has increased the level of antibodies, intensifying the allergic reaction which results in clinical signs.

In dogs, the clinical signs associated with food allergies tend to present in the skin or the gastrointestinal system. The skin can become inflamed and very itchy, this is known as pruritus. The dog will scratch and traumatise the skin which may lead to secondary skin infections with yeast or bacteria; these can be widespread or localised to areas such as the paws or ears.

Alternatively, or in addition, the food allergy may present as gastro intestinal upset with flatulence, increased faecal output, vomiting or diarrhoea. Research has shown us that common food allergens in dogs include: Beef, Dairy, Wheat, Egg, Chicken, Lamb, Soy and Pork.

It is estimated that more than a third of dogs with one food allergy are allergic to at least one additional food and may be allergic to environmental factors too. The presentation of inflamed and itchy skin is similar with environmental and food allergies but a food allergy won’t change with the seasons and can present at a younger age; environmental allergies don’t tend to be seen in puppies less than 1 year.

Adverse Food Reaction (AFR) is a term used to encompass food allergies and food intolerances. In contrast to an allergy, a food intolerance will occur on first exposure to that food or additive and occurs without an immune component. An intolerance is due to an inability to process or digest that food type. This is the case with a toxic substance or where the dog is lacking a specific enzyme that is required to digest the dietary component – eg Lactase is required to digest the dairy sugar Lactose and if you lack Lactase you will be Lactose intolerant.

A diagnosis of food allergy is made when the trigger is eliminated from the diet and the clinical signs resolve but the symptoms return when the allergen is reintroduced to the diet. Novel protein diets (ie protein to which that dog has previously not been exposed) or hydrolysed diets (where the protein is reduced in size to such a level that it is not recognised by the immune system) are used to diagnosed food allergies. Once a food allergy has been diagnosed the effective treatment is avoidance of that food.

No food will be universally hypoallergenic, it is only hypoallergenic for the individual if it avoids all the things that dog is allergic to.

If your dog has any food intolerances or allergies, please don’t hesitate to get in touch. We have a huge range of different recipes to choose from, and can always put you in touch with our vet or nutritionist to discuss your dog’s requirements.