Thank you Astrid
I have mixed a bit of the new organic mix in with his existing mix as a gradual changeover and give him a couple of science selective pellets as well - he really likes the changed mix and takes most of it - and the science selective pellets. These have changed - they are no longer little heart shaped biscuits but kind of brown littler things. Whatever. Contents seem the same. I've found he prefers the junior rodipet mix to the senior so got the junior organic one.
Yes his fur is looking much better. Still a slight baldy patch at that side but not as bad and the skin is a bit dry there. I think it's an age thing. He is ageing gracefully.