This year is one of those years when you need to be extra careful about pet food. Buy a brand that you can buy on both sides of the border.
You see, there is bird flu around. & poultry is often used as protein in pet food. Thus, if the border stations are likely to be told to implement the 'confiscate' regulation, that's when bird flu is around.
If your pet is on a prescription diet, carry the documentation from your vet.
:C