Add 2 - 3 tablespoons of canned pumpkin to his food. (not the pie filling...you want plain with no sugar.) This works great for loose poop! Curiously, it also works for constipation. Not sure why, but as a long time dog owner, I'm not compaining!

weed30 -- Thank you for the pumpkin idea. I spoke to our vet today, and she's on board with that. She says her Border Collies love pumpkin; it should help by adding fiber.

Now I wonder if it will help Eliot sleep! Don't we talk about pumpkin and turkey putting people to sleep after Thanksgiving dinner? LOL

Hi Chisue--remember me? I posted years ago about getting a Westie, actually my son getting one. I have Oski most of the time now, and he's a very fun dog, 3-1/2 years old.

Sorry to hear about Eliot. Were you able to find the plain pumpkin? Is it in a can? Is he better?

OK here are my thoughts. Usually diarrhea or loose stools that do not clear up in a couple days are the result of a parasite. I treat my dogs and cat on a regular basis (about once every 3 mos with a praziquantel/oxibendazole wormer). I buy these medications from this place. They do not require a prescription. (They are located in Australia so weights are listed in kgs rather than lbs on the package label, but both metric and American weights are listed on the website.)
http://www.pets-megastore.com.au/advanced_search_result.php?search_in_description=1&keywords=wormout&x=27&y=9

48 hours after a single treatment if a dog is still symptomatic, they most likely have one of two protozoaic parasites, giardia or coccidia. I treat for giardia first by giving a single dose of the wormer mentioned above on 3 consecutive days. If this improves things, then repeat after 10 days or two weeks.

If giardia treatment does not work, treat for coccidia. This link explains this treatment and is very helpful.

http://www.beaglesunlimited.com/health/coccidiosis-diagnosis-treatment-and-prevention

Many animals including dogs carry coccidea or giardia, but many have no symptoms and only develop diarrhea under stressful conditions. Your dog can become infected through contact with other dogs or through drinking water from a puddle, brook, or pond where the protozoa lives.

I hope this proves helpful to you. I'm in the process of treating my own dogs for coccidia after unsuccessfully trying the giardia treatment. They developed diarrhea after spending a few days at a daycare/boarding kennel while we were out of town. Thankfully they are responding to the sulmet coccidia treatment.

I share your pain. Nothing is more frustrating than dealing with the mess, and witnessing your dog's discomfort, during a prolonged bout of diarrhea. As the writer of the article at the above link writes, you can spend thousands of dollars at the vet on repetitive tests that seldom show the parasite responsible for your pet's affliction, and the end result is that your dog suffers untreated for months.

I hope this helps you and that your dog feels better.