Hello Pamela, I'm Dr. Deb and will do my best to help you today.I'm sorry that Scamp isn't feeling well.I agree with you that I would expect a "simple" gastroenteritis episode secondary to stress to be resolving by now. The fact that it's not indicates that there could be something else going on although I suppose since he's a little older that it might take longer for him to get past his current issue. But, other possibilities include:1. He picked up a viral or bacterial infection from the kennel. These conditions are often difficult to prove but can often take 5-7 days before running their course.2. It's possible the stress of the kennel visit has triggered some, other, underlying medical condition which he's been able to mask until now.
3. He could have internal parasites as a cause for loose stools and he's becoming a little dehydrated which is why he's lethargic.
If this were my case, I'd want to consider blood work to rule out problems with his kidneys, liver or pancreas.If he's getting dehydrated, then he may need fluids...either intravenous or under the skin.He may need stronger drugs to control his symptoms which would have to be prescribed by your vet.If he just continued to have looser stools for a few days, I might not be as concerned but the fact that he's lethargic is worrisome.It sounds to me like a recheck visit would be prudent.I hope this helps. Deb