By Dr Daisy A. May MRCVS BVSc (Distinction), Veterinary Surgeon

It’s official: dogs aren’t small, furry humans! Whilst we sneeze, weep and wheeze our way through hayfever season, our four-legged friends are more likely to suffer from a different – if equally infuriating – symptom: itch.

Itchy skin, itchy ears and recurrent ear infections…not to mention the itchy feet (oh such itchy feet!)

The nibbling, licking and scratching can seem endless, and as a veterinarian I’ve seen canine allergies keep many a dog and many a pet parent up at night!

What you call “allergies”, I as a vet have different names for. Generally speaking, if your vet says your dog may have allergies, they are referring to one of two possible conditions: atopic dermatitis (AD), or cutaneous adverse food reactions (CAFR). These aren’t really as complex as they sound: AD basically means dermatological (skin and ear) problems due to the presence of allergens in the environment, such as pollen. CAFR means skin and ear problems due to food allergy. Where food allergies are to blame, signs of gastrointestinal upset such as vomiting and diarrhea may also be present.

So, what should you do if you think your dog has allergies? Here’s a step-by-step walkthrough of the exact process that I take my clients through, when they arrive in my consult room with an itchy dog in tow.

Formulating a Management Plan Tailored to Your Dog

1. Rule Out Other Possible Causes

Not every itchy dog is itchy because of allergies. Parasites such as fleas and mites, household substances such as laundry detergent and pet shampoo, bacterial and fungal skin infections and even some types of skin cancer can cause itching in dogs. My first step is always to rule out the other causes, through history, clinical examination, and if necessary lab tests such as skin swabs or biopsies.

2. The Dreaded Diet Trial

Once we’ve ruled out other possibilities and settled firmly on allergies as the cause of the itch, I’m going to make your life incredibly hard and expensive. Not intentionally, but I doubt that will soften the blow! How am I going to do this, you may ask?

I’m going to get you to conduct a strict, 8-12 week food trial feeding a (unfortunately rather pricey) prescription anallergenic food exclusively. Please take note that “exclusively” here means no titbits, dental chews, human foodstuffs or other treats! For the duration of the diet trial, your pup needs to be fed only his one designated non-allergy-inducing foodstuff. Failure to comply with this seemingly simple (but often broken) rule will result in a diet trial that is not diagnostically useful, and you will be made to repeat it!

This seemingly torturous process is necessary, because a diet trial is by far the simplest, most reliable and most cost-effective (cheapest) way for me to establish whether your dog is itchy due to a food allergy or not.

If after 8-12 weeks your pet is symptom free, then all you need to do is continue to feed a non-allergenic food and your pup will remain delightfully symptom free. If the problems persist despite the anallergenic food (and you can honestly say with your hand on the bible that you did not cheat on the diet trial), then we can safely throw food allergies out the window, and effectively confirm that your dog has atopic dermatitis, or – to put it more simply – environmental allergies.

3. Allergy Testing (Sometimes)

As a general rule, there is only one good reason to bother carrying out an allergy blood test, and that’s if you plan to pursue allergen specific immunotherapy (ASIT) as a treatment option. This treatment option basically involves vaccinating an allergic dog with increasing amounts of the thing(s) they are allergic to, on a regular basis (usually monthly), in the hope that they stop reacting to the allergen(s).

Of course, in order to create the allergy “vaccine” (which is tailored to your dog), we need to know exactly which thing or things your dog is allergic to – hence allergy testing.

If you aren’t planning to pursue ASIT, allergy testing for canine environmental allergens is practically useless in my books. Here’s why: let’s say you find your dog is allergic to several types of grass and tree pollen. Are you going to keep him inside for the rest of his life? Yes? Well, joke’s on you then because he’s probably also allergic to house dust mites and the yeast that live on his skin as a normal part of the skin microbiome. Bummer.

So, unless you’re pursuing ASIT, allergy testing is effectively pointless, because preventing exposure is entirely unrealistic. Management with medication is pretty much mandatory, for all but very mild atopic dermatitis.

4. Formulating a Management Plan Tailored to Your Dog

Now that we’ve established your pet has environmental allergies, we can go about trying to manage them effectively so that their disruption of your dog’s life (and yours too) is as minimal as possible. To achieve this, I’m going to recommend lifestyle changes and practical measures, as well as discussing medication and supplement options.

What constitutes a great allergy management plan varies dramatically from dog-to-dog, and so you’ll need to work with your own vet for this one. But to give you a rough idea of what to expect, it’s likely to involve some combination of mechanical removal of allergens from the skin; allergy medication; omega fatty acid and/or vitamin E supplementation, and possibly also medicated shampoos or ear cleaners. Every dog is different, but be reassured that a life free from itch is possible; it just takes time to get it right.

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