Be sure to report this situation to the owner immediately. Explain what happened and how it happened. Above all, stay calm. You can also contact the animalhotels.com team. Although animalhotels.com is only an intermediary between carers and owners, and is not responsible for damages caused by pets, we will be happy to help you solve such a situation. We will do everything in our power to make each party happy.
To avoid unpleasant situations and make claims for damages easier, you can construct a contract in which you include that any damage caused by the pet will be covered by its owner.
However, to prevent such incidents, fill up all of your pet's free time. Playing will tire him enough that he will not want to destroy your things. In addition, in the case of a dog, opt for longer walks and outdoor activities. If you have the opportunity, go for walks more often: a tired dog is a happy dog.