The person that wrote this blog http://www.ferretharmony.net/2013/04/27/hairballs-eat-an-egg/ said that with 20/20 hindsight, she can see that the weeks she feeds her kitty eggs, she doesn't throw up (her kitty seems very much like Mazy!) And when I ran out of egg yolk lecithin, Shel threw up (a couple?) hairballs - and it stopped within a day or two of re-starting the lecithin. :dk: