Shoot the cat or see a quack/pharmacist)
(I was only kidding, don't really shoot it-try everything you can to negate the symptoms- wooden floor, posh hoover from Dyson, anti-histamines - (check with your ame), wash the affected part(s), (eyes/nose/throat) with isotonic saline, frequently, try some steroid spray, or spray the poor thing down daily in a fine mist of water).
Herbal remadies may work, but check their product licence.