I received a text from owner the next day after watching dog for a few hours stating the dog had diarrhea. How do I handle this?

Just came here to say, anxiety from any change in environment and/or routine can affect a dog's bowels. It can be considered non threatening if the dog is still eating and drinking, isn't lethargic, and the problem resolves within 1-2 days. I'd be comfortable saying it's even more likely in puppies.

Any dog or puppy injests/consumes anything other than their usual food- even if it’s a higher quality (including food, treats, and anything found outside) , it’s extremely common for it to result in diarrhea.

If you’re going to watch dogs at your home, do yourself a favor and actively monitor the bowls so that each dog only eats the food that they’re given. This includes your dog. If you can’t physically stay next to the bowl the entire time food is on the floor, you can crate or gate them individually while the dog eats.If your dog is used to free feeding, you may find that you have to pick up bowl from the floor and offer throughout the day, never leaving food unmonitored.

The go to remedy for diarrhea is white rice- plain, unseasoned(no salt nor spices), boiled and served room temp or cold, which can be mixed into food. Consider it Nature’s Cork. On the other hand, Pumpkin can go either way. For some dogs pumpkin will solidify their stool and for other dogs pumpkin will make the stool even softer, runnier, more diarrhea. A lot of vets will recommend a bland diet of plain unseasoned boiled chicken mixed in with white rice for a couple days.