generally needle gauges range from 16 to 30, can get most thru vet supply
and at most feed stores. I have given penicillin in smaller than 18. The
horse version is not as thick as the human version. You can get by with
the 20. I use 21s for people instead of the 18. I just have to push harder
to get it in fast. With the new disposable needles, pain from the needle
going in is not much of a factor unless you resterilzed and reuse the needle.
Don't forget to aspirate. I have had more blood returns from injecting
horses than any human and I do 100s of humans. A vet showed me to put the
needle in first and then attach the syringe. That way you know if it is in
a blood vessel and can move to another injection site.
If the horse moves and you are holding onto the syringe, you will
definitely be hurting the horse and he will move even more. Good
luck.
An 18 is much larger than a 20, but necessary for some things
such as Penicillin. That being said, if you are giving PNC, take it out
of the refrigerator, draw it up in the syringe, and warm it in your hands for
a few minutes. It will hurt the horse less and be easier to
inject. (I assume your are giving a med to a horse?)
If you have a choice of giving the med with a 20 or 18, definitely go
with the 20. Trust me on this one.
