Dog Food Allergies

Claire Dunling

Over the last 25 years, more people have been identified as having food allergies or intolerance. The most common offenders are foods like nuts, wheat and lactose. Veterinary science is following hot on the heels of this human trend and now dog food allergies are now more accepted and understood. Here’s a look at the strategies for coping with a dog with food allergies…

Allergy, intolerance or upset tum?

Digestive upsets can be triggered by bad food, a radical change in diet, infections or even stress, however a “reaction” to one of these factors doesn’t necessarily indicate an allergy. An intolerance or allergy is a much wider issue. In an allergic animal the immune system over reacts and produces antibodies to food substances, which would normally be tolerated in the body. Dogs with a dietary intolerance will exhibit allergic symptoms, yet dogs with a full blown allergy could become very unwell indeed.

Dog food allergies: The symptoms

The key symptoms of a dog’s food allergy is a dramatic increase itching or continuously upset digestive system (you’ll know it when you pick it up). Other, more subtle, changes can occur including hyperactivity, weight loss, lethargy or aggression. These changes are not sudden and one day you will realise that “Bouncer never used to do that…”

What types of food are the usual suspects?

The most common food allergies in dogs are those to dairy products, beef or gluten (from wheat). Every time food containing these products is eaten the antibodies react and symptoms either in the form of a gastro intestinal upset or, more usually, skin irritation can erupt.

So these are the only foods dogs are allergic too?

Virtually any ingredient can produce an allergic reaction. Proteins are the most likely cause but other substances can never be ruled out.

Is there a dog food allergy test?

Usually, feeding an elimination diet has been the best method of means to determine the presence and cause of a food allergy. This entails feeding the dog a different, hypoallergenic diet that’s designed to eliminate as many common allergens as possible. This is fed for one to two months to establish an allergen free baseline. Then elements of the previous diet are re-introduced in single meals. If the dog’s allergy symptoms quickly return then one cause has been isolated.

Sadly a sudden switch of diet, particularly to a blander ‘allergy’ free diet may not be something your dog appreciates and they may not want to eat it. If they steal or scavenge anything during the elimination period you have to start whole baseline period again. It’s also worth considering that in multi-dog households, feeding one dog an elimination diet may prove almost impossible.

Problematic factors, such as these, have led to the development of blood tests available which give a surprisingly accurate indication of  what allergens are present in your dog’s diet. It requires a blood sample, but it is a more effective approach to identifying what they can and cannot eat. The other main way of diagnosing individual causes of allergy is by ‘skin testing’ where the vet can identify what causes the allergy from reactions (little lumps) on the skin after testing is done.

Dog food allergy treatment

Once tests have identified the causes (as it may not be a single food), it is then time to get a veterinary expert to identify which brands and makes are free of the offending substances. There is an increasingly wide range of canine hypo-allergenic diets. So, finding a food they can tolerate and will actually eat is getting easier, however if their allergens are less common you may have to consider cooking food specifically for the dog.

Can dog food allergies be cured?

It is not possible to cure a dog for a food allergy, so management (avoidance) is the only real option. There is also the possibility that other food allergies or at least sensitivities may develop as your dog grows older, however the most likely cause for any outbreak of symptoms is that the dog has stolen or accidentally been given the original forbidden food. So, have a proper check of the bin and look at what you’ve fed them before jumping to any conclusion!

This post is an opinion and should only be used as a guide. You should discuss any change to your pet’s care or lifestyle thoroughly with your vet before starting any program or treatment.

If in doubt contact your veterinary practice

And always keep your vet's phone number handy - just in case!