
Well for starters, much as it may not be so important with a smaller breed, my buy in Basset, after years of breeding my own, came to me at 4 months having been fed Royal Canin Junior. When I checked the protein level, I almost died. And indeed, this puppy was HUGE. To me, it was clear that he'd really put on way too much growth, too fast. Yes, a big part of that would be down to his bloodlines, but for sure, we'd never reared our puppies on that level of protein!!! And they all ended up sound. Sadly not so with him. By around 7 - 8 months he was lame on a front leg. As it's around in my breed, I immediately went to Pano and off we went to the bone-specialist vet at the practice I was using at the time. He felt him all over, and had me trotting him up and down outside. He advised full x-rays, front to back. He was able to rule out Pano, and Wobblers (which I'd also considered might be going on - it too is around in the breed) but what he did see was pemature closure of the growth plates, ulna, both sides. This is also not unknown in the breed and I have to say could have happened regardless, BUT would it had he been on a food with a more sensible protein level? We'd never had any of that in our bloodline!
Whether you keep your puppy on this is totally up to you and for sure, many breeders swear by it but I'd not touch it, leaving aside the 'fillers'. Obviously I switched him to another brand, gradually, mixing the new with the old but the damage had already been done. As a result of this, his front has bowed (although actually doesn't look as bad as I'd expected but it's still not good enough for me to feel happy about showing him, which I'd hoped I might be able to do, to get me back in the ring, even if just locally. It's tragic because he's a lovely boy - and a good job because those early months he cost be as much again as his buy-in price.
We have used Burns (not with very good results) but after he was found to have Giardia too

switched him to a fish and potato diet to get his digestive system to settle down. Arden Grange Sensitive. That did the trick. I have just recently switched both mine to Pooch & Co Tripe and Rice which seems to have worked!
I have no experience of Orijen.