Being prepared is part of the process of expecting the unexpected when traveling with your pet. The rest involves being observant. You know your pet better than anyone, and although its behavior in a new environment can be startling, you're in the best position to deal with it successfully.
Watch your pet for signs of frustration and aggression, like growling and lip curling. Be aware of its needs by remembering the last time it used the litter or went outside. Know where your pet is at all times. Supervise playtime with young children and other pets. Schedule and prepare for your pet's bedtime by making sure its sleeping area is ready and comfortable.
Watch your pet for signs of discomfort or distress and keep a first aid kit for small injuries. Make a special effort to spend time with your pet through the day so it doesn't feel neglected or abandoned. Keep your pet's safety in mind. This includes keeping your host's property secure, making sure that your pet is safe in the car or on public transportation, and watching for other animals or pets that could be a danger to it.
Always have health information and a photo of your pet available, and make sure that your pet is wearing identification that will help reunite it with you if it gets lost.
Some of these steps may seem unnecessary for a brief trip, but remember, it only takes a momentary lapse to cause an injury or lose your pet. Your host is relying on you to make your visit a safe one, and it's your job to protect your pet and everyone it comes in contact with.