
Generally speaking, it's usually best to be guided by a reputable, knowledgeable breeder - nobody knows better what works for their breed, and more specifically their bloodlines. I'm all for not piling in a food that's high in protein - and that's often coupled with too much of virtually everything else. Not all food suits all dogs so perhaps the best, initially, is to ask the breeder. Having said that, my most recent bought-in Basset was on Royal Canin Junior which has a protein level WAY higher than anything we reared our puppies on. And although it may have always be going to happen (not unknown in the breed) he went lame around 7 - 8 months which took me to Pano. He had full front to back x-rays but it wasn't Pano but premature closure of the growth plates (I'd left it for a few more months before getting the x-rays done), ulna, both sides. The result eventually was too much turn-out in front, even for the breed! I was warned about the possibility of arthritis (we opted for no surgery and it would probably have meant more than the one in any case) but he's over 6 now, and fine. We had him on antiinflammatories for the lameness initially and he has had a couple of 'episodes' since but not for over a good number of years now (watch, he'll go lame now I've written that!). And actually the degree of turnout isn't as bad as I'd initially thought it would be. I've seen worse in the ring!!
If you do switch, choose a product that's no higher than 26% protein and don't go for the 'breed-specific' food - this usually only means the size of the kibble is different. And one that lists meat, or fish, as the first, main ingredient. Don't go for a cereal-based food.
Add - My Whippet came from somebody I'd class as a good breeder but she used Beta. This I'd not normally touch so after almost finishing the bag she gave me, I switched her onto Burns Puppy at the time. They are both now on Arden Grange Sensitive because in addition to his growth plate problems, my Basset had Giardia early on which left his digestive system 'sensitive'. On AG Sensitive, for a number of years now, he's been fine other than a recent colitis episode following a routine dental ...... (long story - not for here now). A repeat fecal re Giardia proved to be negative, for anything.