my 2 year old cat has this thing every once in a while aboutonce or twice a day. it seems when he starts to purr he makes this wheezing sound kind of like trying to hack up a hairball but nothing comes out. it seems to happen when hes purring and it lasts about a min. it scares me each time cause it seems he cant catch his breath but then when its over hes just fine again. i have asked the vet but he dont really know says it could be asthma or maybe just saliva that when he purrs he cant control. any of u ever hear of this. i guess it dont seem to be a big prob with him i just pet him and be there during it.