"Chicken fat" is considered a reasonably high quality ingredient in pet food formulas, as are most named animal fats. Poultry fat, on the other hand, is an ingredient to stay away from.
AAFCO definition of poultry fat:
Obtained from the tissue of poultry in the commercial process of rendering or extracting. It shall contain only the fatty matter natural to the product produced under good manufacturing practices and shall contain no added free fatty acids or other materials obtained from fat. It must contain not less than 90 percent total fatty acids and not more than 3 percent of unsaponifiables and impurities. It shall have a minimum titer of 33 degrees Celsius. If an antioxidant is used, the common name or names must be indicated, followed by the word "preservative(s)".
Knowing what we now know about the "raw product" of the food rendering industry, note that poultry fat does not necessarily come from slaughterhouse chicken – or even from chicken.
It can come from anywhere, including "4-D animals" – dead, diseased, disabled or dying prior to slaughter. It might be chicken, or it might be turkey, geese, buzzard, seagull, unidentifiable roadkill with wings, or a pet bird euthanized at an animal shelter.
If your pet food contains Poultry fat its a cause for concern about feeding that food