Atopy and allergy aren’t the same thing — and the distinction matters for diagnosis, prognosis, and treatment. Here’s the difference, the breeds at risk, the pattern of symptoms, and what you can do.
The short answer
Atopy is the genetic predisposition to develop allergies. Allergy is the symptomatic reaction itself. A dog needs to be atopic to become allergic — but being atopic doesn’t guarantee they will be.
The long answer is worth understanding, because it shapes what you can and can’t do about it.
What atopy actually is
Atopy is the genetic predisposition of a dog to produce high quantities of IgE (immunoglobulin E) in response to environmental allergens — pollens, house dust mites, moulds, cat dander, certain foods.
Genetic factors are central. Atopy can be passed from generation to generation. It is also silent: atopic dogs do not necessarily display symptoms when they encounter allergens. The only way to identify atopy itself, separate from any allergy that develops on top of it, is through allergy tests that measure IgE levels for various allergens.
So atopy is a condition for the development of allergy — but it is not itself allergy.
What allergy is
Allergy, in veterinary terms, means a dog develops symptoms upon contact with allergens it’s sensitised to.
A dog needs to be atopic to become allergic. But if a dog is atopic, they won’t necessarily progress to an allergic state. Not all atopic dogs develop allergy symptoms. Exactly why some do and others don’t is still being investigated. The current thinking is that environmental factors added to atopy may push some dogs over the threshold into clinical allergy — or, as some newer research suggests, that expressing allergy requires both an atopic predisposition and other inherited genetic factors not related to IgE production.
How to think about it
A useful simplification: in atopic dogs, the pet inhales an airborne allergen, but instead of sneezing and sniffling like a human would, the pet gets itchy skin.
The full picture is more complicated than that. The allergen isn’t only inhaled — it’s also in direct contact with the skin. It’s no longer considered accurate to think of atopy as purely an “inhaled” allergy. How we get from particles floating in the air to itching and scratching isn’t entirely understood, but the important point is that the allergen comes from the air.
Airborne particles — pollen, dander, mould spores — are harmless to a dog who isn’t allergic to them. Allergy develops in dogs who are genetically programmed to do so.
Breeds predisposed to atopy
Some breeds are over-represented:
- Dalmatian
- Golden Retriever
- West Highland White Terrier
- Shar Pei
- Labrador Retriever
- Cairn Terrier
- Lhasa Apso
- Shih Tzu
- Boxer
- Pug
If you have one of these breeds and they start scratching, atopy is worth keeping in mind as the underlying predisposition.
How atopy presents
Pattern of itching
There are many reasons for a dog to itch — parasites, flea bite allergy, food allergy, secondary infection. The clues that point specifically toward atopy are:
- Seasonality — in early stages
- Young age of onset
- A pattern that worsens over years
Seasonality
In dogs, atopy usually produces a seasonal itchiness at first. After several years, the duration of the itchy period extends. Ultimately, in 80% of cases, the dog is itchy nearly all year round.
In cats, unfortunately, seasonality is not nearly as reliable a feature.
Age of onset
Seasonal itchiness due to atopy tends to begin early in a dog’s life — between ages 1 and 3 years in 70% of dogs diagnosed with atopy. By contrast, food allergy tends to begin later, more like age 5 or 6.
Age at onset is not as reliable a sign in cats as in dogs.
Diagnosis vs management
If you think your dog is suffering from atopy or an allergy, the first task is to try to identify what’s causing it. Your vet can run blood tests and intradermal allergy testing to narrow down the offending allergen.
In practice, identifying the trigger conclusively is difficult, expensive, and often inconclusive. Most allergic dogs end up being managed for symptoms rather than cured of an identified cause.
What you can do at home
There are several things you can do without waiting for a definitive diagnosis:
- Feed a high-quality diet. Many dogs improve within a few days when the feed is changed. Cheap fillers and common allergens (soy, wheat, beef, dairy) are worth eliminating first.
- Keep the house dust-free and well-ventilated. Dust mites are a major atopic trigger.
- Wash the bed regularly. Pollen, dander and dust mites accumulate in bedding.
- Vacuum often. Especially in carpets and upholstery.
- Wipe the paws and belly after outdoor walks during pollen season.
How Dermagic helps
For the itching, hot spots and skin damage that atopy and allergies produce, Dermagic products are designed to soothe and protect without resorting to steroids. The Skin Rescue Lotion treats early itching and small inflamed patches before they escalate. The Hot Spot Salve handles established raw spots. The Peppermint and Tea Tree Oil Shampoo and the Skin Rescue Shampoo Bar cleanse without stripping the skin’s natural defences.
The goal is consistent: support the skin’s own immunity rather than suppress it.
For specific guidance on your dog’s case email info@dermagic.eu or call 01624 829575.