Half of Spaniards do not know there are cats considered hypoallergenic. That figure comes from Sanicat's first Feline Barometer, and it is interesting not for the number itself but for what sits behind it: an entire industry lives off the idea that if you pay more for a particular breed, the allergy will pass you by.

The American Academy of Allergy, Asthma and Immunology says otherwise. All cats produce allergens. There are no truly hypoallergenic breeds. Full stop.

It is not the fur, it is the saliva

This is the part most people get wrong. We say "I'm allergic to cat hair", and the problem is not there at all. The main culprit is Fel d 1 - a protein present above all in the animal's saliva and skin.

When a cat grooms itself, and it does that dozens of times a day, that protein ends up on the skin and on the fur. From there the tiny particles pass into the air, stay suspended or settle on sofas, carpets, clothes. The allergens are also present in urine and other secretions. That is why a sensitive person can get sneezing, a blocked nose, watering eyes, a cough, even difficulty breathing, especially with asthma.

In other words: you are not buying a breed, you are buying a quantity of protein. And that quantity varies from cat to cat, not only from breed to breed.

The only test worth anything

Breed on its own cannot predict how a given person will react. That is why Sanicat's recommendation is not a list of breeds but something far more boring and far more accurate: spend a longer stretch of time with the specific cat before deciding to take it home. Not one afternoon's stroking in a pet shop. Time.

If the reactions are serious or respiratory symptoms appear, the first step is not any breed - it is an allergist. That is the sentence that makes nobody any money, which is why you hear it least often.

The house carries responsibility too

Specialists advise keeping the cat out of the bedroom, washing hands after every contact, cleaning often and using HEPA filters. Sanicat adds one more detail few people take into account - litter tray hygiene. Litter that controls urine well, produces little dust and is not perfumed.

So the three things that realistically determine tolerability are: the specific animal, the sensitivity of the specific person, and how disciplined the upkeep of the space is. Not one of the three is solved by the price in a listing.

And Jennifer Aniston?

The story started with her because the actress, a well-known animal lover who has lived with dogs for years, is allergic to cats. Asked whether she is more of a dog person, she replied: "Sorry, cats, I'm a dog person" - and immediately clarified that the reason is the allergy.

That is a situation far more common than it looks, and it does not automatically have to mean giving up. But it equally does not mean there is a breed that will solve the problem for you.