The Tibetan Spaniel is a highly revered watch dog in Tibet. There the dog was used in Buddhist monasteries to watch out for approaching strangers and wild animals. Upon spotting visitors or animals, the Tibetan Spaniel would bark to signal the guard dogs to be ready to defend the monastery. The dogs were sometimes referred to as "little lion dogs" as they kept faithful watch over the monasteries and accompanied monks as they went about their business. The dogs were so highly revered that they were often given as gifts to different nobility in China.
They continue to have a great temperament for use as a watch dog. They are highly intelligent and somewhat independent. However, they like being around people and prefer to find perches like the nearest accessible windowsill to use as their watch stations. From there, they will sit and watch the perimeter of the house, warning the householders with insistent barking if anyone dares approach. Since a visitor often can't see the size of the dog, they may be quite intimidated by this show of barking, but the truth is that the dog is not very aggressive. It is a very amicable pet and only barks to warn people, not because it wants to defend the house or bite anyone.
The dog is also active at night. If it hears a disturbance during the night it will also start barking. This can be a very good early warning system and can deter people who might be trying to break in. It doesn't matter that your dog will probably back up if the person actually got in, because the bark alone is a very good deterrent. It will also alert you to the possibility of danger long before it becomes an emergency.
This dog won't sleep outside and prefers to be part of the family unit. You can separate it at night to have it sleep somewhere other than your bedroom, but it will wake up bright and early when it expects you to be up and start barking if you don't get up. It is not only watching the house but also watching you and expecting that you follow a routine. This may be a little difficult to deal with, but the dog will often settle down if it hears you moving around.
The dog is not a good watch dog with children. It just doesn't like to be around small children. This is possibly because they are very energetic or there is the potential for teasing. Either way, this dog prefers a very calm household and makes an ideal pet for an elderly person who needs a good watch dog.