What do you feed your collie?

[fivedogstofeed]

I have a beautiful collie staying with me and he has been eating Milllies Wolfheart Salmon & Veg as this is what all my dogs eat. It's clearly not agreeing with him :(
Is fish a bad choice for collies? or is it too much protein?
I've fed dozens of foster dogs on the same food and never had an issue, so I'm really surprised but desperate to get something nutritious for him.

I feed mine Natural Instincts complete raw working dogs food. He looks superb on it and loves it which is a blessing as he’s not a great fan of food. The lab/springer cross is a different matter and would probably eat the collie if he stayed still long enough.

Meant to say I give him the salmon one and he’s fine on that so fish obviously not a general collie issue.

blobby very similar lab x here...