There's a guy at my school who finished with me - he's doing animal behavioural psychology, with a mind to going on to train dogs. Try ringing up the major training schools in London (there's a fair few) and asking if you can speak to the owners, and possibly getting work exp there, or an internship. Look at local classes, speak to those people who do it there - look it up on the web, look at UCAS for animal psych, and go to the institution pages in order to see what their degree entails.