You can give canned pumpkin that will help firm up loose stools. Not the pumpkin pie filling, but pure pumpkin....
I give it to Riley as a random treat... The can says it is good for 3-days after opened. A friend sent me a can and said that what she does is puts it in a large Sandwich baggie and flattens it out as much as possible. She then breaks pieces off of it. I did the same thing and he just LOVES it!!
This is the brand he has:
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