Making safe, healthy dog biscuits

Question
My friend and I are thinking of going into business together making and selling dog biscuits.  What should I avoid?  Are food coloring and decorator gels safe?  Do you have any advice/tips?

Answer
Hi Chrys;
You will have to do quite a bit of research.
Some vegetables and herbs are poisonous to dogs, but not to cats and humans, some are poisonous to all animals but not humans, so you have to find all thay out first.
Put this in your search engine, and check out all the sites you get up, make sure none of the ingredients are harmful to them, make a few, and check them out with your Veterinarian.
put in         homemade dog biscuits, recipes
               recipes for dog treats
               
Those should get you some sites with recipes.
Good luck. Hope you build a good business and do well.
Charlotte