Feline asthma is a life threatening disease.
It would be best to have a full work up first by your veterinarian and use steroids,inhalers and other medications, if necessary.
There are excellent adjunctive treatments that can be tried once the asthma is well controlled. Herbal formula's can be gradually increased and can sometimes replace steroids, but since there is no cure for asthma, oral Prednisolone and Asthma inhalers must always be kept at hand for emergencies. Upper respiratory infections can exacerbate asthma, so constant monitoring is essential.
The Chinese herbal remedies: Bu Fei and San Ao Wan are good adjuncts to asthma therapy, but should not be given without veterinary supervision.
Hi, is your vet positive that it's asthma? Has your vet made absolutely certain that it's not her heart causing the breathing problems?