I have a dashound that had the runs on fri night seams to get over this even thought they are still a little lose my dog is eating and asking for her dinner
She is normal quite lively when around people but dose sleep a lot but seams a little of colour still and not as lively as normal

Have you changed her diet at all? I know this can have the same effects. If not and your dog is lathargic (laying around all the time won't move) then you should take him to the vet and get it checked out, that's the thing with animals they have many of the same symptoms for many different illnesses. Has you dog been around any new or strange dogs lately? Did you see any blood in the stool? Has he been getting sick?