Muzzle (mouth guard)

Muzzles are sometimes used on trained and untrained dogs, large or small, to prevent unwanted biting, scavenging, or wound licking. They can also be used on dogs who display aggression, whether motivated by excitement, fear, or prey drive. Muzzles are also used on dogs when there is a risk of them taking baits that have been laid for vermin.

Muzzles can also be used on racing dogs and working dogs (military, police, security, etc.).

They are usually made with a strong buckle or other fastening device to ensure that they do not come off accidentally. The most suitable materials for dog muzzles are leather, nylon, plastic and others. The most comfortable muzzles for dogs are those with wire cage construction. Muzzles of this kind give enough freedom for a dog to eat, drink and freely pant. The latter two are of vital importance, especially in hot weather.

Dog muzzles can be found in most pet supply stores.

Donkeys wearing muzzles

A grazing muzzle on a horse

Certain muzzles with a wire-like structure are used on horses and related animals, usually to prevent biting or cribbing. Other types, known as "grazing muzzles", have a small opening in the center that allows limited intake of grass, and are used on obese horses or on those animals prone to laminitis or choke, to prevent them from eating too much or too fast.

Horses trained for airscenting, for search and rescue or police work, often are worked in muzzles. This helps to keep them focused on their work, because they cannot easily snatch bites of grass.

Horse muzzles may be purchased in tack shops or from equestrian supply companies, and are available as a halter attachment, or as a separate piece of equipment.

A device under development in England to reduce greenhouse gas emissions aims to capture methane by placing a muzzle on the cow's nose, which converts the methane they burps into carbon dioxide and water.[1]

• Elizabethan collar
• Spit hood