My Billy had terrible asthma from when he was really young. For the first half of his life, he was getting a steroid shot every single month. When we changed vets, our vet got him down to 2-3 steroid shots a year by having us give 1/2 a tablet of Zyrtec once a day and an albuterol rescue inhaler. Then, at 14 years old, he became diabetic. He's in remission now, but no more steroid shots. He gets his Zyrtec daily, has his rescue inhaler, which he uses once or twice a day when he's having trouble, and he has a steroid inhaler called Flovent, which we only use when he is having enough trouble that he needs more. Basically, the Flovent has taken the place of the steroid shots. For example the spring and fall, he needs his Flovent. Inhaled steroids do not tend to raise blood sugar like oral or injected steroids do.
So far, he's been in remission and off steroid shots for over a year, and is doing well. In fact, he's doing great.
One other thing that helped Billy is that we discovered he has food allergies. We used 5 Strands DNA testing to see what foods and additives he was intolerant of. Then we ended up changing to a limited ingredient raw diet, because he was allergic to so much. Since his food change, he has not needed his steroid inhaler at all.