Try a little bit of no shell unsalted sunflower seeds!! It worked for my puppy who is very picky.. The smell it's strong and she loved it!! I couldn't believe how much she ate with a little bit of that on her food! That's what worked for me last night and this morning! I don't think they can eat a lot of it and make sure it's unsalted... if you can't find unsalted then just do salted and maybe clean the salt off but don't give your dog too much either way... not sure how much of that they can eat but apparently its safe for them in small quantities.
Let us know how he is doing. I will keep Teddy in my thoughts and prayers!