well i guess none of us can be sure anything we consume today is good for us, they are always changing their minds, i think marmite is ok, i let me kids have it, so i reckon the cats will be ok with it to be honest, it is a bit salty though i must agree with you on that. Anyways it was just something a vet said on the tv, that a small amt everyday on their paws can help with furballs, cant be any worse than the stuff in the tube, whatever is in that.