One day the time could come when you need to leave Hong Kong.
The good news is that these days exportation is fairly straightforward. As long as your dog or cat is up to date with their rabies and combination (G6 or F3) vaccinations, they can travel to most countries (including the UK, Europe and North America) at any time without any quarantine. You will need to arrange some paperwork and health certificates, as well as booking space on the plane for the pet.
Animals travelling to Australia, New Zealand, Singapore, Indonesia, Hawaii and Japan have more detailed requirements and although quarantine is generally very short they may need up to six months to prepare before export. We'd recommend using a professional pet exporter for any pet travel, but especially so for these countries with more complicated requirements. There are a number of pet exporters listed in the Travelling with Pets section who can help with arrangements. And remember to contact them well ahead of time as requirements can change, and flights can be difficult to book.
It is also possible to take your pet on holidays overseas to many countries, but usually special blood tests and paperwork are required. It's also not cheap - and some people think their dog or cat would actually prefer just to relax at home.