[theBCnut]

No, but it could speak to the dog’s stress level. I don’t mean stress in a bad way so maybe I should say excitement instead. Gut motility is affected by how “on” a dog is, so when he is out on a fun or exciting walk then everything could be passing through his large intestine faster than it can draw the fluids out. Adding a little fiber to his diet may slow down transit and even everything out, but it might not. I would try sprinkling 1/2 teaspoon of plain metamucil or a generic equivalent on his food and see if that does the trick.