A change to my first review.
I previously gave Thrive a poor review as it gave my Kitten very loose/ smelly poo, which was a shame as I liked the high meat content and lack of fillers in Thrive. Unlike many brands Thrive state it is suitable for kittens upwards. However once my cat reached 7 months of age his bowel movements have normalised, and on trying Thrive again he has been fine. So it is possible that Thrive might not be suitable for younger kittens with immature digestive systems.