Make sure there are no chemical preservatives listed on the label. Look for words like ethoxyquin, BHA or Propyl Gallate. If you see these on the label, take heed. Ethoxyquin is usually used as a preservative in many pet foods it might be hard to avoid it. Ethoxyquin can have toxic effects. There is still much debate as to whether Ethoxyquin is dangerous or not. Though it is listed as a hazardous chemical by OSHA Hazard Communication Standards some the FDA are still saying it is harmless. When you are deciding on the right diet for you dog, do your research to determine how you feel about Ethoxyquin as an ingredient. You can find tons of information on it, on the Internet. Also note that Ethoxyquin can also show up on labels as just E.