Very helpful info. Thank you for sharing.
I had inserted the needle with the procaine into the breast for 4 days and it worked. A year later she was sick again. I injected the needle same place and she violently reacted and jumped out of my arms, slammed herself to the floor repeatedly and died. It was horrible to watch. So I asked my vet where else to inject and maybe I injected into the wrong spot??? He said to put needle under the skin between the leg and body, that loose flap of skin. And I did this for another sick chicken and it worked, so it was not a muscular injection.