What is immunotherapy (ASIT) for cats?

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, meaning reversing the natural course of an allergy and training the immune system to stop attacking the allergens and learn to tolerate them instead.

So far, this is the only treatment of this kind and is available for atopic cats 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 cat’s atopy.

This liquid is injected under the cat’s skin just as a vaccine is. In the beginning, a loading regime over 12 weeks 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.

This maintenance dose of 1 ml is then 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 cat 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, 75-80% of the cats show marked reduction of symptoms, to the point of not needing medication for their flare-ups.

The product is very safe and easy to administer, most cats tolerating injections under the skin without any fuss. The liquid itself is of water consistency and not stingy at all. For cats specifically, a sublingual form of the immunotherapy preparate exists that can be given under the tongue.

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

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