It's that much used phrase "meat and animal deriviatives" whcih includes heads, feet, gut, lungs, feathers etc. By products of the meat industry (ie the bits humans don't want to it!). manufacturers don't have to list what is included. Meat deriviatives is rendered and has a different definition to meat by products. Meat can include organs and quite a lot of yukky stuff. Nothing wrong with a bit of offal, but I do sometimes worry about exactly what is included. I feel happier with named meats - I forget now but I think there is a legal definition of what can be included if you name the meat - eg. chicken. I do feed by products in some foods though and think EU regulations are tighter than those in the US. I may be wrong, but I think pet food in the EU has to come from animals passed fit for human consumption whereas in the US they can use animals that are not fit for human consumption.
I will pick up a couple of cartons of the Toplife food at the weekend and see how well it goes down.