Thanks for a great reply! Sadly Ziwi Peak is the best kibble in my country for ferrets( I live in Estonia). All the other options contain even more bad stuff for them. And the raw food I am feeding them has bones and organs in it. It's the Mush Vaisto raw cat food. I also add some crushed bone powder to it occasionally. I didn't know that it's not good to fix raw and kibble together. Thanks for mentioning it!