I am so happy to hear that dusty is getting better.

You vet is right if a cat cannot smell it's food it is likely that it will not eat. That is why a stuffed nose is so bad.

The coughing/hacking, does it sound more like sneezing or more like dusty may be trying to throw up?

If it is sneezing and he is not stuffed up, then it may be tha the gets into something that is dusty and he is just sneezing because of that. I do not know how young hairballls start, but I would imagine they can started as soon as they begin to groom themselves. Hopefully someone else will have better ideas.

Once again I am really glad that he is eating and seems to be doing better. I hope that is continues.