[Mary N]

I agree that you must check this with the vet. There can be so many different issues causing a poor appetite in dogs.
Just check these out:
http://pets.webmd.com/dogs/guide/dog-not-eating-possible-causes-and-appetite-solutions

And I assure you that the list goes on and on. Do the blood work and check out what might be a problem.

Also if it turns out that everything is well, which I hope it will, then you can try some things to amplify the smell of the dog’s food.

Like adding homemade food. I see that you wouldn’t want to cook it yourself, but you can make a bunch and add just a little bit to your dog’s bowl every day. That might work.

Also, make sure that your dog is tired enough and he will eat better.

Still, you can’t do much without the vet visit. If there is some health problem involved you would only be making it worse by exercising your dog of feeding it homemade mix.