I am currently watch three dogs and one of them chewed up another ones foldable dog bowl. What should I do ?

The first concern is the dog’s health and any potential medically related consequences - did the dog chew it up and leave it in pieces or are parts of the material missing/ingested. If it’s simply damaged beyond use, breathe a sigh of relief & message pet parent with an update. It might go something like “ Fido communicated that he wanted more food by chewing the foldable dog bowl. Luckily, it does not look like he ingested any part of it after playing with it. (Insert photo) This is what Fido left behind. Sorry to share the news”

Chances are good that they will not expect you to replace it. By letting them know, they may be able to order one to be shipped to their home before they return home.

Now that you know what these dogs are capable of, you’ll likely put things they can damage out of reach for their own safety.

In addition to Deb's advice about ensuring the dog hasn't eaten any of the plastic bowl, you are going to have to tell the owner what happened. I realize this was a different dog's bowl, not the one who chewed it up. Tell them the truth that another one of your boarders destroyed it. Offer to replace it. They are very cheap. You can find them at pet stores and even places like TJ Maxx/Marshalls/Home Goods for less than $10. I have a folding bowl that I have taken when I needed to put out a bowl of water for my dog when we're outside or at the park.

A number of my regular boarders arrive with traveling cases that owners keep handy. Those folding bowls are often in them, along with other necessities. However, I NEVER use them. I have my own metal bowls for guest dogs. Several of them, in fact, for the dogs' food and their water. As you've unfortunately found out, a dog's possessions can get ruined especially when there are other dogs around. I am very careful when an owner brings their toys as well. Whether I put them out depends on which dogs might be here. My own dog will ignore but I have a couple of regulars who are destroyers by nature.

Many sitters specifically do not allow personal possessions in their homes. But you have to make the call based on your knowledge of a dog's past behavior. I wouldn't worry too much over this bowl. You can easily replace or offer to do so.

Finally, when you have multiple dogs, you have to monitor very carefully. Not only do they eat in different locations, but I pick up their bowls when they've finished as it is quite normal for dogs to thoroughly check the other bowls just in case a morsel remains.