In a large bowl, combine the pumpkin puree, coconut oil, cinnamon, and water. Stir well to combine.
Add the oats to the pumpkin mixture and stir well to fully mix the ingredients.
Using your hands, roll the mixture into appropriate sized treats for your pets.
Place treats on a baking sheet lined with wax paper. Refrigerate the finished treats for 24 hours before serving to firm the pumpkin puree. Store in an airtight container in the refrigerator. Treats will last up to 2 weeks.