I also think it's hairballs. I've got a lot of experience with the hacking/choking/coughing that comes with hairballs - unfortunately. Petromalt works great. There are other brands that are basically the same thing, so if your local store doesn't have Petromalt specifically, they should have something similar. Tubby likes to eat it right out of the tube. Peanut, not so much. So I put some on her foot and she proceeded to flip her foot, consequently flipping the Petromalt all over the wall.

So if you get some and Josie won't eat it right out of the tube, rub some on her foot, don't just squeeze it on or you'll be wiping Petromalt off your walls too.

Good luck and hopefully this will do the trick. I used to give Tubby some every morning and it really helped.