Allergic skin disease in dogs

Signs and Symptoms

Allergies in dogs can show up in lots of different ways but the most common things vets see are symptoms affecting a dog’s skin.

Itchiness (vets call this PRURITUS) is the most common sign but dogs can also develop recurrent skin infections, or sore, greasy or dry skin.

Obviously if a dog is itchy they are likely to scratch: ears, armpits, belly, bottom- they can be itchy anywhere.

Head shaking and paw licking are also a sign that your dog may be itchy.

Some dogs may roll around on their back, rub against furniture or objects, or drag their belly or bottom along the floor.

It may look funny to see your dog spinning on their bottom, or doing a commando crawl across the carpet, but it’s far more likely that they are itchy rather than just clowning around.

Allergies in dogs may appear to start suddenly, or they may develop gradually.

Most allergy symptoms start in young adult dogs, around 3-5 years old.

THIS is not a hard and fast rule and vets are seeing more and more dogs diagnosed with allergies when they are puppies, or as older dogs.

Allergies may be seasonal, making your dog itchy for just a few weeks or months, or they may be present all the time matter whether it is spring, summer, autumn or winter.

Sometimes allergies may start off seasonal but gradually last longer each year until eventually your dog is itchy all the time.

What is my dog allergic to?

Like people, dogs can be allergic to almost anything.

Vets break allergies down into two categories:

FOOD allergies and ENVIRONMENTAL allergies.

Environmental allergens may be things in the home (dust mites, storage mites) or outdoor allergens
such as pollens or plants.

Often, dogs are allergic to more than one thing.

Food allergies can be identified with a diet trial, while environmental allergies are diagnosed with skin or blood
tests.

Managing Allergies

How you manage your dog’s allergies will depend on what they are allergic to, how severe the allergy is, and what the symptoms are.

For some dogs with mild or limited symptoms, topical treatment may be sufficient.

This can include ear cleaners, topical steroids, or topical treatments to help improve the skin structure
and quality.

For dogs with more generalised or severe symptoms then oral or injectable medication may be necessary.

One of the best ways to treat allergic skin disease is with immunotherapy.

This is giving your dog increasing doses of allergen given over a period of time, usually by injection to desensitise your dog to whatever he is allergic to.

If your dog’s symptoms have resolved with a hydrolysed food trial then you can either feed the hydrolysed diet long term, or try challenging your dog with individual foods to see what they can tolerate.

Whether your dog has a food allergy or is allergic to the grasses and trees in the park, using consistent flea and mite treatment is important.

They may be coping well with their allergy but if they get fleas then that will make their symptoms a lot worse.

Why is my Dog so Itchy??

Parasites

If a dog is scratching then the first thing to check for is PARASITES: fleas, mites and lice can all make your dog itchy.

Your vet will perform a close examination of your dog’s skin and coat to check for signs of fleas, and examine his ears with an otoscope to check for ear mites.

Superficial skin scrapes may be needed to check for Demodex or Sarcoptes mites which can infect the structures of the skin.

Often the best way to rule out whether parasites may be causing your dog’s pruritus is to do a treatment trial with a good-quality flea and mite treatment.

You may think this is a waste of time and money, but if your dog has lots of tests and investigations, only to find out months later that it could all have been fixed with regular flea treatment, you won’t be too impressed:

If in doubt, rule it out.

Infection

Skin infections can also make your dog itchy.

Infection can be caused by bacteria, yeasts or fungus.

Infected skin may be red, have broken or no hair, and may have spots, scabs, or flaky patches.

Ear infections usually cause head shaking, sore red hot ears and a waxy smelly discharge.

Your vet may be suspicious of a skin or ear infection after examining your pet.

Infection can be confirmed and identified from samples collected with cellotape, cotton buds, or swabs for cultures.

A one-off skin infection can be treated and resolved.

In pets that get skin or ear infections over and over, there is probably an underlying cause that needs to be
identified and treated.

Hormonal Disease

Sometimes skin changes including itchiness can be due to an underlying illness such as Cushings Disease or an underactive thyroid.

Both of these can cause changes in your dogs coat and skin which may make skin changes, infections and
pruritus more likely.

Your vet can do blood tests to check for underlying disease that may be making your pet itchy.

Allergies

If your vet has ruled out parasites and infection, and checked for underlying disease but your dog is still scratching, then an allergy may be to blame.

Allergies in dogs can be seasonal or year round; they can cause generalised pruritus or just affect a limited area (ears, feet or face); they can start when your dog is young, middle-aged or older; and dogs can be allergic to things in the house (dust mites, storage mites) or outside (pollens, grasses, trees) or they can have a food allergy.

Your vet can run tests to identify what your dog is allergic to and help you decide how best to manage it.