A muzzle gag is a form of gag most common in BDSM activities. A muzzle gag consists of a piece of fabric, usually leather, which fits across the entire mouth of the subject, effectively blocking lip movement. Unlike other gags, a muzzle gag requires more extensive buckle-straps, both horizontal and vertical, to remain secure. Occasionally, items may be stuffed in the mouth for further effect, as a muzzle gag does not restrict tongue movements or block throat noises. Instead, it tries to block all sound as it leaves the mouth.
Muzzle gags are fairly rare, and are rarely used in spanking scenarios. Due to the nature of the muzzle, many people feel increased humiliation when forced to wear one because, like the bit gag used on horses, it is a modified item primarily used for restraining dogs and other animals.
This type of gag is featured in the 1991 BDSM video Spoiled Sluts for the Dungeon Mistress from London Enterprises.