I use a 20gage, needle that is 1/2" long for all my goats. The only time i find I need a different one is when I have to give a shot that is thick, and I need a bigger size (smaller gage) needle. I hope I have that right.
I use 1/2 inch 20 gauge, but I prefer 22 gauge if I can find it. Chelsey, where do you get 29 gauge needles? :?