All...we moved to HK from USA with our 2 cats two years ago. Basically you need to make sure you have the right vaccinations and documents for entry. Pets will travel as cargo like the last poster mentioned. As long as all your documents are prepared and you are not coming from a Group III country, then there should be no quarantine.
Here's the latest website from the HK Government:
http://www.afcd.gov.hk/english/quara..._ipab_idc.html
Documents needed for dogs & cats are:
1/ Import permit from HK Government. Look at website how to apply.
2/ Health certificate dated not more than 14 days before departure
3/ Residence certificate
4/ Vaccination certificate
5/ Airline Certificate
--> See HK Government website for more info
For Group II countries (includes USA & Canada) as long as you have all these documents and pets are > 5 months old there will be no quarantine.
I DO highly recommend using a pet exporter who's specialized at helping your pets get into the country without problems (at least for peace of mind). You can look locally in your country for the service or try export-a-pet in HK (like last poster mentioned) or
www.wishyouwereherehk.com (the company we've used).