Well a little update, just as we were going to the vet to change her food for the science CD, lexie decided it was toilet time, very good timing as i discovered she was now constipated, i had been gradually adding her new food, but i think too much, i had no advise given, but knew you only did it over a week or so, i think half of each was too much, poor wee girl, so we had to get something from the vet, which is hard to administer and messy and she hates, i think it is parafin oil, it has done the trick, but gosh poor lexie has been having it so rough ,poor wee lass, i have ordered the royal canin, i am sure it is the one for her, after reading all your comments, i really value your opinions and i am sold on it,more so than the vets really, as you all have experience, i doubt they have really, of course i am not so keen having to alter her diet yet again, but i guess we will get there in the end, i sure hope so, as this is hard on her and me,she was always such a content girl on her old biscuits.