Well Al that is one dam good question...I have browsed both the customs web pages in search for bringing fish to the show and bringing fish back in...and was not able to make heads or tails in the end.
As for foods as you speak...I assuming commercial packaged dried foods that show the ingredients may just be fine.
The links below may assist somewhat...
https://www.thestar.com/life/travel/...to-canada.html
https://www.crossbordershopping.ca/d...t-animal-guide
...Ralph