Make sure any food you bring to the U.S. does not contain beef or mutton/lamb.

On the customs forms you receive on the plane, there are questions about what you are carrying, including if you have any meat products. Do say yes, because if you don't and they find your catfood, it's an expensive fine and you and the cats might be on the next plane back to where you came from.

However write on the form "commercially prepared, canned meat product" - that statement comes from advice I've been given by the ag inspection people. They will ask to your cans. According to some regulation related to the mad cow disease scare, beef from countries which have had mad cow outbreaks in the last 10 years is not allowed and will be confiscated - like the cat treats we tried to bring into the U.S. The fish flavor was allowed, the beef was confiscated. For reasons that they did not explain, the ag inspectors also confiscate mutton/lamb based products.

So if you have poultry/fish/rabbit/venison cat food, it should be allowed in.

Why are the cat/cats flying cargo to the U.S. and not in cabin?