petromalt...or any cat hairball medicne.....give 1 inch everyday for one week (for each ferret) you can give 1/2 inch but i give 1 inch per ferret for one week...then give every 3rd day from here on out...take their poop and smash it in tolit paper if they are passing hairballs you will see hair...migh look like little cocoons of hair...its gross but you should do it anyway...YOU WILL BECOME A POOP EXPERT!!!!!! i am...ugh!!! your panicking makes you a great mom... ;-) i have 8 ferrets and i do the same thing.... sincerly, Trudi [Posted in FML issue 2463]