Are there agencies that help low income persons with veterinary care and supplies for their pets? I live in MO

This link...

https://www.humanesociety.org/resources/having-trouble-affording-veterinary-care

... takes you to a search engine to look for free or low cost providers near you, for the veterinary care.

What sort of supplies do you need? For what kind of fur baby?

Dleecious1, if you live in an area that has a "Food Panty" service or similar name, check to see if they also have a "Pet Panty" where people donate new bags and cans of pet food.

Pets are so very important in keeping our elderly happy, and there are times when their income can no longer afford to feed their pet properly.

humanesociety.org/animals/resources/tips/trouble_affording_pet.html

This is a website for caregivers of the elderly, not pets. There is inadequate funding for social services for humans. Contact a local shelter or the Humane Society.