I think that some with asthma have real problems but they already know so would not have a cat.
My sister is very bad if in contact with fur and stuff and had to vanish back to the car after being in my house for a few minutes. She loves cats but swells up if she gets scratched or anything and she and animals of any sort just dont mix well......and she probably would end up in hospital but thats not the right way to be.
She cant even have a flu jab cos of the egg/chicken thing...yes she doesnt just have asthma but his highly allergic too.
I dont know if something like this can happen suddenly although I know her allergy probs did.
I know a doctor said I had asthma and gave me all the medicine to take but read the notes and thought , I dont like sound of this and went back. She said go for a jog, well a fast walk round the block and come back........and I was better in the test after, than before