Our pup has had an upset tummy on and off for the last 6-8 weeks. He basically has loose stools and every once in a while will throw up. The vet checked him out and nothing appeared to be wrong, but he put them on flagyl for 2 weeks and it cleared up some. As soon as he got off flagyl, it came back. We switched his food about 3 weeks ago to Canidae thinking that he may have a wheat allergy but it's really not helping. We tried rice, yogurt, chicken, etc to firm his stools up some but its not working. We started on pumpkin last evening hoping to firm up his stools again. FWIW his first stool of the day, right after he gets up in the am, is pretty firm. He is a happy puppy, active and no other symptoms that he isn't feeling well.
Thanks!
Re: How long to give pumpkin?
From what I understand (we just started our Jasper on pumpkin for similar reasons to yours) you can give pumpkin as long as you want/need. A lot of the other pesties use pumpkin and give it daily as a treat (frozen cubes) or mixed in food.
I posted a question about pumpkin a day or so ago, and might have some information you're looking for.
Here's the link: http://community.thenest.com/cs/ks/forums/thread/63595839.aspx