Hi there,
my Golden Retriever pup (she is 4 months) has been fed on the James Wellbeloved puppy food range. Last time we were at the vets I was told that she is very slim, and I should feed her more. But she always left half of her food, even if I added some cooked chicken to entise her to finish her meal. After a lot of research I have decided to change her food to Royal Canin Maxi Junior. She now eats all of her food every time in about 30 seconds, no kibbles are left in her bowl ever. I wonder if she didn't like the James Wellbeloved food? Or is it normal that dogs like a new food more than their usual one? Have you had similar experiences? Or different ones?

Fussy pups really are a nightmare- especially when you need to get a bit of weight on them! IMO she may have just not liked the JWB, not all dogs like everything. She may also just like the new food as it is new... my girl can be a bit like this too. To try and get her to eat more, I put her food down and let her eat as much as she will. Some days she licks the bowl clean, others she turns her nose up. Whatever is left I stuff into a KONG or hollow bone and she seems to see this as something different and finishes every little bit. If you haven't already, maybe try adding some grated cheese or mackerel to her food as well, it's so stinky they can't resist! Good luck- I know how frustrating it can be!

Yes is very hard when you have a fussy pup...i gave mine nature diet puppy food mixed with their complete,just makes it a bit more inviting.

I've found all of mine go a little off their food at around 4 or 5 months as they start teething   nothing to do with being fussy, more to do with sore gums

So at 4 months she may be teething, you could try soaking her food in hot water (not boiling) so she doesn't have anything to crunch   this will also make the food more inviting

IME changing food for fussy pups just makes them fussier - and there's nothing worse than a fussy dog I've been there - never again!