Patch had terribly offensive wind, fairly loose fluffy big poos, too. I read around, and asked at the behaviourists and the vets.
Burns Potato and Pork was suggested. I introduced it very gradually, 5 weeks ago, over 10 days. He seemed to like it and is still very enthusiastic about it. However, he has lost 2.5 kg in weight.
I contacted Burns today, and they said that he's probably getting used to the lower fat content of Burns. They suggested adding an egg or two in with his meals, and/or some vegetable oil.
I told her how thin he'd become, and that I could see his ribs, but she said that she thought perhaps I'm overthinking his shape, because her dogs ribs can be seen when lying down.
BUT he's led next to me. I can see each and every rib. I can see each vertebra of his spine. His hips feel bony. In fact, my DD's carer came in today and said 'he looks like a concentration camp dog'.
I've done my best to provide him with a good quality food. His bowels seems so much better, but the weight loss is a worry. He's almost 1, and now weighs 15kg, down from 17.5kg 5 weeks ago.