Marmite for cats? You cannot even be sure it's good for humans (sorry for that, I have friends in NZ -so I know what you're talking about).
No but seriously I think there is too much salt in it -the rest is yeast and herbs which can do no damage. There is dry food with a hairball control formula. I agree with the others- brushing and thinking about a lion cut. I've seen Bunny's Fluffy last week in that cut -he looked so elegant and impressive.