I would look at all possible angles particularly the medication perspective as this may be your big ticket selling point. Many of us pet owners find it hard to keep track of meds particularly when we have more than one furbaby.
Reach out to vets as some previously recommended but you may also want to reach out to a manufacturer like Merck Animal Health. Your product could improve their sales and their products performance if meds are distributed more consistently.
You might also want to reach out to private shelters - rescue groups and animal sactuaries, even zoos. Big Cat Rescue in FL, Liz E's Pekingese Rescue in Arkansas. They could share with you the challenges they have in making sure animals are getting their meds and/or treats.
I'd be happy to discuss further if you'd like.
Best of luck!