Well thats why i spoke to her again before i gave the injection to be sure as i have only ever seen them given in the top of the body before and no were on the net mentions the tail.

The next one is due in a couple of days so im going to go as described in the video you posted. I feel more comfortable that way but kinda felt i had to bow down to the (apparent) superior knowledge of the vet.

Thanks again for the advice guys and ill keep you posted