Food Allergies

How to identify a food allergy

The only meaningful way to identify if your dog has a food allergy is by performing a strict

FOOD EXCLUSION TRIAL.

As vets we often recommend performing one of these for a dog with an allergy, as it is important to know if it is FOOD causing an allergy compared to something else.

The treatment for a food allergy compared to an environmental allergy are very different.

Unfortunately there is no other meaningful way (don't waste money on testing kits you can buy online) of testing for a food allergy. A food exclusion trial relies on you as an owner doing it properly otherwise the results are meaningless.

If you have been asked by your Vet to do a food trial, we urge you to read this carefully and try your best to do it properly!

How does a Food Trial work?

A Food Trial works by feeding your dog a special diet for 6-10 weeks. We do this by finding a diet that doesn't include any ingredients your dog has eaten before (as this is what they will potentially be allergic to), and over the course of the food exclusion trial, seeing if their skin improves.

It is likely your dog will be on medication before a food trial (to alleviate the itching), but If your dog's skin becomes less itchy during the food trial your Vet may be able to suggest stopping or reducing the medication. If at weeks 8-10 your dog is no longer itching or on any medication for itching, then this is likely to mean your dog DOES have a food allergy. However, to confirm this, we have to RE-INTRODUCE all of the original foods as proof that the itching re-starts., which means the food MUST be the cause of the allergy (ie, the allergy hasn't just got better for another reason as a lucky coincidence).

The flip side, is that during the food exclusion trial there is no improvement at all to the skin, thus showing a food allergy to be very unlikely. This means you and your Vet can focus on managing an environmental allergy.

How to perform a Food Exclusion Trial

Commit to doing a food trial - everyone involved in feeding your dog needs to be on board. ALL food needs to be part of the trial, otherwise it is a waste of time. The aim is for 8-10 weeks
Decide on the food type to feed. This MUST NOT include any ingredients your dog has eaten before. The diet is used just for a trial period, and so you are not committing to feeding your dog this forever. (see options below)
Liase with your Vet to confirm when this is starting, and discuss any medications your dog is currently on and to check in with your Vet regularly to see how the trial is going.

Food options:

Hydrolysed Diets - These have been manufactured to effectively destroy any possible allergens within the food. They are balanced diets, but often not the most exciting for a dog to eat. Probably the easiest option for a diet trial.
Home cooked diet - This relies on choosing a new protein and carbohydrate source, something your dog has never come into contact with. Combine ONE protein (eg. Quorn, Insect, kangaroo, ostrich, camel ) +ONE carbohydrate (eg. sweet potato, chickpeas, beetroot, green peas). Batch cooking is a good idea, and aim for 200grams protein + 400grams carbohydrate per 10kg dog. NOTE this is not a longterm balanced diet, but for the period of a food trial will be adequate.
Limited Ingredient Diets - these diets have been made out of a very select few ingredients. Providing you can confirm your dog has not eaten any of the ingredients before, this can be an easier option than a home cooked diet.

Lifelong Management for Food Allergies

FOOD

Your Dog's Diet will be crucial in managing their allergy. By avoiding the foods that trigger the allergy, this should prevent their skin allergy from flaring up. During your Food exclusion Trial, you will have identified a diet that your dog can tolerate, and then through time you can very slowly try out (through trial and error) adding in single proteins and single carbohydrates to create a tick list of what your dog can (and cannot) tolerate.

Some owners choose to continue on a pre-manufactured hydrolysed diet, particularly if their dog eats it. If doing this, you could always add in extra protein or carbohydrates to make it a more varied diet for your dog.

Maintain Skin Health

It is important to keep your dog's skin as healthy as possible. Skin supplements containing omega 3 & 6 fatty acids have been shown to help this, and are worth using (providing your dog can tolerate them).

Regular flea treatment is important to prevent your dog's skin getting irritated by fleas, and carefully monitoring their skin for flare ups.

Watch out for changes

Skin allergies can change over time, so watch out for changes in your dog's skin or how they react to different foods. It is possible for environmental allergens to develop, so check in with your Vet regularly.

Food allergies