We recommend : 21 G or 23 G needle
23 G is smaller and 21 G is bigger.
When you need to inject more GS 441524, or Cat is not good to handle, so the 21G needle injection is faster.
You can try it first. some of vets say 23 G is suitable, others say no, they can’t handle but 21 G is much easier.
Some of cats are happy with smaller needle, but some of cats need the bigger ones.
About syringe :
We have syringe with thread 3 parts.
You can turn the needle on it, so it sits more firmly.
That is better with the thinner one.
Then it cannot jump off due to the pressure.
These syringes are not cheap, but with thread for needle.
When you like to use 23 G needle, you can try “3 parts syrings”