Cynthia Smillie's 11-year old dog named Tao-tao unexpectedly started to 'virtually break down the door' when she went to bed. Every night, when it got dark, Tao-tao would become more and more anxious, and try to hide. Eventually, Smillie suspected the cause of her pet's distress was the low-battery sound coming from a mobile phone. With a condition called separation anxiety, some dogs that are left alone suffer anxiousness and negative behaviour. 'Separation anxiety is a fairly common behaviour in dogs,' Smillie says. 'They will show fairly marked signs of distress when the owner goes away. Some destroy doors or demolish kitchens - they can literally tear the place apart.' As each dog displays signs of the condition differently, other behaviour can include barking, whining, urination, defecation or destroying personal items such as cushions or shoes. According to Smillie, any breed can suffer separation anxiety and it can start at any time. 'The cause doesn't have to be related to the owner's departure. It can be a frightening sound for the dog, like the low battery,' she says. 'Any kind of trigger can make the dog anxious while [the behaviour is shown] when the owner goes away.' Often, the dog is over-attached to the owner and looks to them for emotional stability. Causes for separation anxiety, Smillie says, can range from changes of circumstances in the home, such as a stay-at-home parent who goes back to work, to older animals that are showing signs of ageing and senility. She adds older dogs have deteriorating sensory perception, which contributes to separation anxiety. 'There are so many motivators [that can cause separation anxiety]. When you treat a problem, unless you understand the motivator behind it, you won't solve it,' says Smillie, a former veterinary surgeon and deputy executive director of the Society for the Prevention of Cruelty to Animals Hong Kong. 'Separation anxiety is a blanket label. Sometimes, when you delve down it isn't about over-attachment, there could be other reasons.' One example, Smillie recalls, involved a dog that suddenly started to damage its home in Sai Kung. Previously, whenever the owner left the home, he would put the dog outside on the patio without incident. But one day the owner returned to find the patio destroyed and the dog trying to escape. On the surface, it seemed the dog was distressed about being alone. However, Smillie and the owner discovered the behaviour was most likely triggered by a wild boar that frightened the dog when it tried to enter the property. Every time the dog was put on the patio it would feel scared and vulnerable. 'This emphasises that you need to accurately pinpoint the motivator behind the behaviour. ... Sometimes the anxiety starts to generalise and affects everything it does,' she says. To remedy the situation, the goal is to relax the dog and reduce anxiety in the home. In the short term, owners can try to take the animal with them more often or get a pet sitter so it isn't left alone. In the medium term, Smillie points out that every time the owner goes away, 'we can never get the anxiety to go down' without medication. Once the dog has been on medication for about four to six weeks, the owner can start desensitisation techniques and allow the canine to spend time on its own. One technique, Smillie says, is to stand outside the door and mark the time between leaving and when the dog becomes anxious. Some start whining after five seconds, while others start after five minutes. However long it takes is the base time. Next, the owner should practise multiple exits, going out and coming back - all before the base time, preventing separation anxiety before it starts. Then, gradually, add on time and increase the period the dog is left alone. Another desensitisation technique involves mixing up all the cues that the owner is leaving. Smillie suggests making a list of the triggers, such as putting on your shoes and coat, then doing something unrelated to departure: having a cup of tea or watching television, and practise this confusion a few times a day. 'Mix up the sequence so your dog doesn't know if you are coming or going.' For those with new puppies, Smillie advises owners to make sure the puppies are left by themselves for short periods of time, so they get used to not having someone there all the time. 'A lot of these dogs are very needy, jumping up and wanting a lot of attention, but it's best to not take notice when they are in a needy, aroused state. But give it plenty of attention when it's calmed down to reinforce relaxed behaviour,' Smillie says. As for Tao-tao, Smillie was able to successfully treat her dog, but it took two years.