I have to inject a sheep with an IM dose. Have done this in groin but not putting anything on its bum this time of year. If I pop it in the rump (she’s a breeder so not worried about carcass) does the needle go in straight or at an angle, and does it need to point in any direction? I’ve not done one before. If I follow up spine towards head from base of tail how far up, and then down the side, roughly do you go?