I thought it would be better to start a new post rather than full up the Puppy survival thread. Also may be useful for others in a similar situation.
I was using Wainwright's mixture of dry and wet food. Was ok, pup liked it but it didn't really agree with his tummy and also the feeding guides are not particularly good so I think he was eating too much. Weight wise he looks ok compared to the guides but vet said top end of ok and could do with dropping a kilo as ribs starting to be less easy to feel than at last vets visit.
Bought some of the vets dry food, transitioned over 5 days (vet gave no guidance but just said mix a small amount in and increase daily which I did). He seemed to eat it ok mixed in, day 5 had all the new food and was ok. Day 6 same but was sick in the evening. The only good thing was that the new stuff stopped him having dodgy poos and also he stopped having wind like he did before.
Since then he won't eat the vets food at all though. I went back to mixing in the old food and he will eat that but spits out the new stuff. However his tummy is back to being not good.
I have bought some Royal Canin breed specific to see if that's any better, on advice I have put in 2 separate bowls , tiny bit of new stuff in one, normal amount of the vets food. He will now only eat the new stuff, this morning he went to the old food but spat it out and barked at it. He's hardly eaten anything as outright refuses the vets stuff.
I am not sure what to do, hes had 15g of dry food last night and again this morning. He's hungry as he keeps going over to his bowl and sniffing it but won't eat it. He also keep going over to the new bowl and licking it so it seems he is looking for more of that.
I guess there could be something else going on and he is ill rather than its the food, but the fact he is well in himself and will eat other stuff suggests that's not the case.
Sorry this is long but I thought I should explain properly to help get the correct advice.