The one who has asthma doesn't actually live with us, he is my husbands son and stays every other weekend. His mum has cats and always has done. I had my two cats before we even met, the bird we got a while back. I'm unsure of if they affect him hugely, difficult to know because he was like that before we got the bird and has always been around cats. As far as I know, his doctor hasn't advised he shouldn't be around pets. I think part of the problem was until I told her otherwise, his mum wasn't using his medication properly so he wasn't benefitting from it as he should have been. He has the blue and brown pumps, the blue one should always be used first to open up his airways then the brown one, to gain the most effect from it. I've read up about it and apparently the brown one should by now have eliminated most of his symptoms if used properly. But because she wasn't using the blue one first he wasn't getting the full benefit from the brown one. This has since changed, after I told her that she should use blue first, last time he came down he hardly coughed at all whereas before he would cough so much he'd end up being sick. We don't allow the bird to fly around when he's here for those couple of days and we vacuum up any seeds or feathers that may have escaped his cage every day. We also keep the cats away from him at all times and remind the other children that they need to do the same with him.
With our LOs bronchitis, I'm not sure what could aggravate it, I know smoke can but we smoke outside, change clothes and wash hands after to minimise anything on us. Not sure about fur and stuff though. We haven't been told by the hospital, I think if it was a major risk factor they'd have said something, but still it's good to be sure it's all vacuumed away anyway