Loki's pattern has been to have diarrhea every 4th day, so if he had it on Tuesday ... he would then have 3 normal days followed by diarrhea. He had it on Saturday but the vets would not accept a sample on a Saturday, it needs to be "fresh" for sending to the lab for analysis. Having been reading online I decided on Saturday to get a bottle of panacur and give him 20ml a day as it is a successful treatment for Giardia. Most dogs become infected with the parasite by drinking water contaminated with feces, as we know these are in every puddle and ditch. Giardia infects the small intestine, and infected dogs pass microscopic cysts in their stool. Giardia is a very common cause of pet diarrhea in the United States and reasonably common in the UK. Should this treatment be successful I will need to keep a close eye on the others for any loose stools as it can carry from one to the other through the cysts passed in the stools.
Anyway, today is the fourth day and Loki has a normal stool. Of course I don't know if Loki had/has giardia, but as I couldn't get the sample tested on Saturday it gave me a chance to eliminate something else from the equation. The panacur finishes today and now it's a case of wait and see. Because of previous experiences with other dogs, I just can't get optimistic yet ...