Ferals get injected with a pole that corners them in the cage.  The needle hits wherever it hits.  Dogs get a cardiac stick.  Tame cats are given cardiac sticks, but this is all assembly line fashion, so it's not uncommon for them o mis and give multiple sticks.  Usually it's an 18 gauge needle or larger, which when giving a cardiac stick to a kitten is the proportional equivalent of an average sized adult human getting an ice pick to the chest.  The Hawaiian Inhumane Society still does sticks but has moved to gassing which is a horror show as well.