The patented dual stage injector prevents ‘premature injectuculation’ . The mechanism will only dispense the NumOcaine once the needle is forward and in the animal at the required angle and depth, defined by the Numnuts device. If the needle comes up against a blockage (dag, stone ot bone in the tail), the dual stage injector provides feedback to the operator to readjust their position and does not waste a dose of NumOcaine on outside of the animal.