just a few tips, for future SQ injections, --
... if you can't get the rabbit to hold still, get some help restraining it.
... if the rabbit is "bucking" don't inject the meds [as you cannot be sure you are in the target injection area, or missing a blood vein]
... avoid using overly long needles, an inch is plenty for a rabbit, 3/4 inch long needles easily pierce the skin, and place meds far enough away from the injection hole to avoid too much "leaking" back through the injection site after the injection. . [overly long needles increase the chance of missing the injection target area]
...use 4 fingers and thumb to pull up the skin between the shoulder blades, [as opposed to one or two fingers and thumb] this makes a longer tent, this reduces the chance of missing the injection target area, or pushing the needle through the skin on the other side of the "tent"
....when inserting the needle into the skin, [tent] have the syringe parallel to the rabbits back [not pointed down toward the rabbit, or up away from the rabbit.
...insert the needle with point toward the rabbits head, not pointing toward its butt.[because, if the rabbit starts to wiggle , and gets loose, the head will come up, causing the needle to be pushed on a downward angle into the spine area]
... inject SQ meds with about a half inch space between the rabbits back, and where you insert the needle into the tent. [this helps avoid accidental IM injections, or spine damage from a misplaced needle].
.. when injecting Pen G or other thick medications, use a larger diameter needle,[ having to use a lot of force to inject meds through the needle, or taking a long time to get the injection completed, increases the chance of accidents , missing the target injection area, as well as increasing the duration of the rabbits discomfort]
again, JMHO