Hee! Good that the marshmallow reputation is still intact!

From what the staff at the local pet store and a bit of digging on the internet have told me, canned pumpkin is one of those cases that'll work both ways. It will clear up both constipation and diarrhea, much like Metamucil seems to do. I'm guessing it has something to do with a huge amount of fibre that either gets things moving or just bulks up depending on what the issue is.

Barney's had two bouts with diarrhea, both times I took away all food for about 12 hours, and then fed him boiled chicken and rice for a few days until it cleared up. I've been continuing to add the pumpkin and Metamucil after getting him back on his regular food, and it seems to be working!

I suggest you provide him with zinc supplements unless the vet contraindicates it. This will help treat diarrhea.

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Bernese Mountain dogs have a way of finding the people who need them, filling an emptiness we don't even know we have.

Our girl is 8 months old and has had 2 or 3 bouts of the runs - we found out that she had beem eating blackcurrants once and another time plums that had fallen from our tree - never realised at the time but watched where she went when ut had cleared up.
To get over it we were recommended, and it worked, starve her for 24hrs, just let her have water, then feed her boiled rice for a day then back on her food. Worked for us every time, found that if we didn't leave it 24hrs it dragged on a bit longer.