I am really unsure what to tell you as I don't know the laws for bringing a cat into Australia. I know they are very strict on bringing any animal there so he may have to endure a long quarentine. I know the flight from London to Toronto is about 7 hours and that a long time but if I am not mistaken it is a much longer flight from London to Australia. I think it is like 14 hours or so. (Not positive on that one though) I really think you both need to talk about this seriously. Do what is best for Sam. If you are looking at a quarentine in Australia you need to find out how long. The quarentine may be too stressful for him. Especially a long one and I really think it is. You can also get a mild sedative prescribed at the vet's so he will be more comfortable on his flight over. Make sure you cover all the basis and do what you both feel is the right and best thing where Sam is concerned. Good Luck and let us know what happens.