Provided is a coupler for use with animals, the coupler having a stopper mechanism that is configured integrally with the main body and is capable of preventing transmission to the slide bar of a movement of the animal being connected as a retracting force. The coupler (SH, SHa, SH2, SH2a) is provided with: a hook section (Ho)； a shaft section (SL, St) that extends from an end of the hook section in a first direction (Ds)； a slide bar (Sb) for opening and closing the hook section by moving back and forth along the first direction； a coupling ring (CR1), which is connected to the end of the shaft section so as to rotate freely with the first direction as the axis and which has a specified external shape that extends in a second direction perpendicular to the first direction； at least one projection (Pr, Bu, Sld) extending from the perimeter of the coupling ring by a specified length in the second direction； and an actuator part (Kn) connected to the slide bar and extending towards the coupling ring. When moved in the first direction, the actuator part (Kn) abuts only against the projection (Pr, Bu, Sld).本發明提供一種具有制動器機構之動物用的連結具，該制動器機構與本體一體地構成，且可防止連結對象之移動作為推回力傳遞至滑桿。本發明之連結具SH、SHa、SH2、SH2a具備有：鉤部Ho；軸部SL、St，其自上述鉤部之端部朝第1方向Ds延伸；滑桿Sb，其藉由沿著上述第1方向進行往返移動而開閉上述鉤部；具有既定外形狀之連結環CR1，其以上述第1方向為軸旋轉自如地連結於上述軸部之端部，並且朝與上述第1方向垂直之第2方向延伸；至少1個突起Pr、Bu、Sld，其自上述連結環之外周部朝上述第2方向僅延伸既定長度；及操作部Kn，其連結於上述滑桿且朝上述連結環延伸；且上述操作部Kn於朝上述第1方向移動時，僅抵接於上述突起Pr、Bu、Sld。
