I buy freeze dried liver treats for my dog. He's fed raw, but my brothers dog is fed kibble. At the bottom of these bags of freeze dried liver treats there's powder left over from crushed treats which I give to my brother to mix in his dogs kibble. Without it she often won't eat.
I used the same technique with my dog to get him to eat fish with some success, but of course this isn't a permanent solution.
See your vet, but it's possible you just need to try alternative foods. I know my local Global Pet Foods sells bags of kibble in sample sizes of about 2 meals for your dog to try, you might consider that.
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