I have got 2 cats. One of them has got the same problem as the one you are describing. Both of my cats are indoor cats. The vet tells me that this problem occurs mostly in cats living indoor. My cats are indoor cats. The problem can be prevented by changing the cat's nutrition. My cats are having specialized food which helps against hairballs. As long as my cats are on the specialized food, there is not much of a problem. As soon as they eat another kind, the problem stars again. I know it is not a pretty sight to see. The poor thing was coughing so fiercely that at one point I thought she was going to choke! Therefore I abide by the food suggested by my vet. The vet also prescribed a paste that the cat can lick of her paws but that was less successful: the patient did not like it at all!