What is immunotherapy (ASIT) for dogs?

Reversing the natural course of an allergy

Allergies are usually described as untreatable and that is true for most of them. But recently, a new allergy therapy was brought on the market, immunotherapy, or by its long name, antigen-specific immunotherapy (ASIT).

The principle on which it is based is called desensitisation and is the opposite of hypersensitivity. Desensitisation means reversing the natural course of an allergy and training the immune system to stop attacking the allergens and learn to tolerate them instead, as it does in non-allergic animals.

So far, this is the only treatment of this kind and is available for atopic dogs only (no other types of allergy yet).

On a practical level, the ASIT preparate is a liquid formulated for each patient individually. It contains small quantities of the allergens known (from serological or intradermal testing) to trigger your dog’s atopy. Up to 8 allergens can be included in one bottle.

This liquid is injected under the dog’s skin just as a vaccine. In the first 12 weeks, a loading regime is followed, starting with a very small dose (0.2 ml), then increasing it gradually every 2-4 weeks to 1 ml, which is the maintenance dose.

After these 12 weeks, a maintenance dose of 1 ml is given every 4 weeks until the bottle is finished, after approximately 10 months. A new batch can be ordered, but is often unnecessary, the atopy showing improvement by then.

If you’re wondering why an allergen given as injection desensitises the immune system of an atopic dog but repeated exposure outdoors to the same pollen or grass makes it worse, the answer is simple. The first is a controlled exposure, using very small amounts while the latter is an uncontrolled exposure, sometimes to gigantic quantities of allergen.

The ASIT’s efficacy is pretty good - 1/3 of the dogs getting immunotherapy will show almost complete resolution of atopic symptoms, ⅓ of the dogs will have significant improvement, though with occasional mild flare-ups and ⅓ of the dogs will show improvement, but not enough to avoid medication during the allergen-heavy times of the year.

So far there is no way of predicting which dogs will fall in which of these three categories, therefore ASIT is recommended for all atopic dogs. The product is very safe, has no side effects and is easy to administer, most dogs tolerating injections under the skin without much fuss. The liquid itself is of water consistency so the injection is not stingy at all.

This type of therapy is recommended by The International Committee on Allergic Diseases of Animals (ICADA), and is widely recommended and used by dermatologists and vets when dealing with atopic dogs.

Should you have other questions about ASIT, book a consultation with one of our vets and they will be happy to help!