This is a topic close to my heart. But now i not the time to buy items from our heart just because the pet food manufacturers try to convince us that their treats are the best for our doggies. Hogwash.
Your best best is to go natural and here is a list of Healthy Dog Treats:
Cabbage: Considered cancer fighting food and good for your dog.
Frozen Sardines: Rich in Omega oils and very tasty
Brown Rice: cooked, yes bland but excellent for upset stomachs.
Red Peppers: Packed with vitamins and a sweet treat.
Pumpkin: Cooked or canned; lose weight, low fat, high fiber, and helps with diarrhea and constipation. Recommend starting with a tablespoon a day.
Apple: calcium, vitamin k, vitamin c, pectin, remove core and seeds and stems.
Quinoa; good for grain sensitivities, and good stomach settler
Carrots: cleans teeth
Cauliflower: raw; not too much, may cause gas.
Cheese: only hard chese, highly caloric, and avoid soft unripen cheese which may lead to stomach upset.
Now every dog is different but these are better alternatives than the stuff bought at stores in my opinion. If you are not sure about some of the treats, always see your veterinarian. I'm a dog advocate, not a dog dietician or veterinarian.