If your pet is well socialized, it'll have a better time visiting a multi-pet household, but even this isn't a guarantee that your pet will get along with the new housemates. When visiting, approach all animal interactions with caution, especially when animals are mismatched in size. Monitor all encounters between your pet and others until you're sure that your pet is assimilating into the new household. Be particularly careful when there are young children present. Animals that are unfamiliar with young children can misinterpret curiosity for aggression and react violently. Instruct young children to be respectful of your pet, and keep playtime under close supervision.
Don't assume that your pet will love all animals because it's always gotten along with animals before. New surroundings and situations can cause your pet to react in unexpected ways. Sometimes this can mean cowering under the furniture, and other times, it can mean growling and nipping. The introduction of new animals or people, loud noises and competition for food can all be triggers for changes in pet behavior. Until you feel confident that your pet won't be a threat to children, other animals or property, watch it closely or keep it segregated in a carrier or separate room.