Ew... That's tragic and disgusting at the same time. I might try that Nature's Gift pet food. It's Australian and they don't use horse meat. They aren't owned by some big evil company are they?
I am trying to find a not heaps expensive dog food until I can start trying some sort of vegan pet food (as they are all currently out of stock) anyhows...I just emailed Nature's Gift and received this response:
"We do test our products on cats and dogs as we are a manufacturer of pet food. The animals sample a variety of our products – canned food, dry food and treats to see if they like it and how many do or do not"
I am now sending them a follow up email to find out if they test on lab animals, or volunteer animals (or alike).
EDIT: I got another reply "they are actually tested on the staffs pets at home"