Food for a shelter dog?

My friend is fostering (two week period before he decides if he wants to adopt) a border collie/ husky/ mix. We tried everything yesterday to get him to eat, with no luck. We got him Taste of the Wild salmon, spits it out. We tried treats, bread, pizza crust, rice, etc, nothing. Eventually later on in the night we tried the treats route again. He seemed to like the really smelly stuff (Blue Buffalo salmon soft squares, puporoni, blue buffalo apple and lamb, blue buffalo bacon health bars) but would continue to spit dog food out. He also denied Blue buffalo blueberry and yoghurt health bars and blue buffalo lamb dog food. So to me, it seems like he prefers the stinky stuff.

When asking SPCA what he ate there before we left, they said it's a mix of all the food they have at a time and then in the evening they mix everyone's food with wet dog food. So that doesn't really help, other than I could imagine it wouldn't be the expensive stuff since they were shocked when I donated a blue bluffalo wet dog food earlier in the day and were extremely excited since they have a sick dog currently.

Any suggestions on what we could try would be amazing, even if it doesn't work.

 

Oh thank you!!! I do have canned tuna in my possession. We'll try that for breakfast and go from there. Thanks!

 

The tuna worked! Thanks so much. He's rather skinny (too skinny) so we were worried about getting food in him.