Wow! This sounds like exactly the sort of niche product that could really take off, with the right channels to market, and strong marketing support. Well done!
I’d encourage your to consider whether you have the expertise / desire to learn how to run a manufacturing operation. I’m really leaning towards contract manufacturing for your product, especially as it sounds like your ingredients are all food-quality anyway, so that should make your options quite wide.
I’d talk to other niche food producers (of human type foods, probably) who are using dehydration facilities. Also have you spoken to the team at the Food Bowl, which I understand has all the facilities to enable you to produce small batches as well?
Good luck! Remember pet owners be CRAZY about treats for their beloved furbabies!