A leash retracting apparatus (20, 100) for automatically retracting a leash for an animal, the leash retracting apparatus comprising: a housing (22, 102) defining an opening (26, 116) for passing the leash; a spool (24, 124) rotatably mounted in the housing (22, 102) for selectively winding and unwinding of the leash, the spool (24, 124) including a hub (40, 126) defining an axis of rotation, and gear teeth disposed about an outer surface of the hub (40, 126); a gear train including a plurality of gears (44, 46, 48, 146, 148, 150), the gear train operatively engaged with the gear teeth on the hub (40, 126) of the spool (24, 124) for rotation of the gears in the gear train; a carrier linkage (42, 140) being rotatable about the rotation axis of the spool (24, 124), the carrier linkage (42, 140) defining a cavity for housing a portion of the gear train for rotation of the carrier linkage (42, 140) about the rotation axis upon rotation of the gears in the gear train, a distal end of the carrier linkage including a radially outwardly extending cam surface (64, 141); a lockout pawl (28, 180) pivotally secured in the housing (22, 102), the pawl (28, 180) movable between a first position that enables the spool (24, 124) to freely rotate and a second locked position to lock the spool (24, 124) against rotation, wherein the cam surface (64, 141) on the rotating carrier linkage (42, 140) is configured to engage the pawl (28, 180) for moving the pawl to the second position; and a control knob (54, 110) being rotatable about the rotation axis, the control knob (54, 110) enabling the gear train to be selectively positioned with respect to the pawl (28, 180), wherein the control knob (54, 110) functions to selectively predetermine a maximum length of the leash extending from the housing (22, 102) before the cam surface (64, 141) on the carrier linkage (42, 140) engages the pawl (28, 180) as the leash is being unwound from the spool (24, 124), causing the pawl (28, 180) to rotate to the second position into engagement with the spool (24, 124) for preventing rotation of the spool. a housing (22, 102) defining an opening (26, 116) for passing the leash; a spool (24, 124) rotatably mounted in the housing (22, 102) for selectively winding and unwinding of the leash, the spool (24, 124) including a hub (40, 126) defining an axis of rotation, and gear teeth disposed about an outer surface of the hub (40, 126); a gear train including a plurality of gears (44, 46, 48, 146, 148, 150), the gear train operatively engaged with the gear teeth on the hub (40, 126) of the spool (24, 124) for rotation of the gears in the gear train; a carrier linkage (42, 140) being rotatable about the rotation axis of the spool (24, 124), the carrier linkage (42, 140) defining a cavity for housing a portion of the gear train for rotation of the carrier linkage (42, 140) about the rotation axis upon rotation of the gears in the gear train, a distal end of the carrier linkage including a radially outwardly extending cam surface (64, 141); a lockout pawl (28, 180) pivotally secured in the housing (22, 102), the pawl (28, 180) movable between a first position that enables the spool (24, 124) to freely rotate and a second locked position to lock the spool (24, 124) against rotation, wherein the cam surface (64, 141) on the rotating carrier linkage (42, 140) is configured to engage the pawl (28, 180) for moving the pawl to the second position; and a control knob (54, 110) being rotatable about the rotation axis, the control knob (54, 110) enabling the gear train to be selectively positioned with respect to the pawl (28, 180),