Initially we were surprised by the questions but have been asked at other borders about the dog food. It's because of the meat products in the dog food. Canada and the US have given us similar questions.
We too do not like to change our dogs food but check the SAMs club there. I was a bit surprised by the variety of dog foods they carry.
To clarify. The SAMs club is just like the ones in the US. The Walmart is owned by Walmart but goes by a different name and looks a bit different from what you normally see but it's all good