Snuffles....(snuffly buns)

Just some questions regarding snuffles (dont worry all my babies are well...but after discussion with a friend regarding their rabbit).....

How treatable is snuffles? My friends rabbit has symptoms of sneezing...sneezing fits, wet nose (greeny/yellow colour) and repeatedly cleaning/wiping nose. He has been on a course of baytril and advised to keep indoors, warm and dry.

Can snuffles be cured? If not can the symptoms be treated, and finally....is this highly transferable to other rabbits?

Thanks

Salt has suffered from snuffles in the past.
He has never passed it to Pepper (his brother).
Salt lives outside, and I believe the fresh air is good for them - blows the dust away! They have dust free hay and straw, and seem to be doing fine.
He had a course of antibiotics before we discovered the dust free hay, but no signs of snuffles now. I'm sure it's lying dormant, but hopefully if he stays fit and well in every other sense, we can keep it at bay.