i mention these because i got them at Petco. All beef liver treat and nothing else. made in the usa.
-stewart-freeze-dried-treats-jpg

Pro-Treat Freeze Dried Treats maintain the aroma, full flavor, and nutritional value of raw beef liver and chicken. Conveniently cubed into reward size treats, Pro-Treat is an excellent obedience and training tool.
Rich in protein.
Packed in resealable plastic canister.

Gimborn Pro-Treat Freeze Dried Beef Liver Treats
4 oz.; Beef Liver
Contents: 100% raw beef liver. No additives or preservatives.

Gimborn Pro-Treat Freeze Dried Beef Liver Treats
4 oz.; Beef Liver
Crude protein (min.) 50%, crude fat (min.) 5%, crude fiber (max.) 3%, moisture (max.) 6%.