Original Item: Only One Available. The M5 and M4 horse gas masks were identical in all but one aspect--the position of the canisters. On the M5, both canisters hung from the right shoulder of the horse. On the M4, one canister hung from each shoulder. The M5 mask was designed for the Cavalry. The soldier on the horse carried his rifle in the cavalry standard on the horse’s left shoulder. In World War II, 39,159 M4 and M5 horse gas masks were produced.
 
Even without the actual gas mask, these items are still extremely rare and scarce to come by. In 1941 and 1942, the U.S. government issued the M4 and M5 gas masks for the horses being used in service. Horses in the Cavalry and Pack Mules were not as common in WWII as they were in WWI, making the Horse Gas Mask all the more rare. The mask carrying case is in near mint condition with only minor staining to the canvas and minor staining around the brass fittings and buckles, leaving a greenish residue. The leather straps and buckles are in perfect working order and condition, displaying no damage or paint loss to the buckles and bales, but there is minor paint loss to the outside flap lift buttons.
 
Markings on the canvas carrier:
US
HORSE GAS MASK M5
Measurements:
13”x12” (while closed and laying flat)
Strap Length 41”
Markings on the canister carrier:
DOUBLE CANISTER CARRIER
HORSE GAS MASK
WHG    1
Measurements:
18”x10” (while flap open and laying as is in picture)
The reason for these items being so scarce is that they were barely used outside of training scenarios and in the event they were brought overseas, the soldiers would usually discard them due to their size.
 
Items such as these seem to disappear daily from history, and in time will soon be forgotten. Give yourself a daily reminder of what these brave men, women and animals went through in the past by adding this set to your collection. It would truly be welcomed in any gas mask, cavalry or equestrian collection!
 
The M4 horse gas mask adopted in 1941 represented a radical departure from previous masks. Chemical agents were no longer destroyed by chemicals on the mask material but were absorbed by two large cylindrical MI canisters carried on the horse’s shoulders. The M1 canister prevented the rifle from being positioned on the horse’s left shoulder, which meant that the M4 mask was intended for working horses. Two hoses carried air from the filters to a T-connection that combined the airflow and sent it to the mask. The M4 mask was made of rubber and completely enclosed the mouth and nose of the animal. It included a rubber mouthpiece for the horse to bite. A mask carrier hung from the pommel of the horse. Few of these masks were manufactured until the need for horses in the Italian campaign created the need to protect packhorses.
 
The M5 and M4 horse gas masks were identical in all but one aspect--the position of the canisters. On the M5, both canisters hung from the right shoulder of the horse. On the M4, one canister hung from each shoulder. The M5 mask was designed for the Cavalry. The soldier on the horse carried his rifle in the cavalry standard on the horse’s left shoulder. In World War II, 39,159 M4 and M5 horse gas masks were produced.
 
The M4 and M5 horse gas masks survived the war as standard issue. Experience from flying animals over the "hump" in the China-Burma-India Theater in World War II showed that horses needed supplied air to prevent undue physical and nervous strain. Both horses and mules needed the air to prevent damage to themselves, the cargo, and aircraft. In 1950, the Chemical Corps Technical Committee determined that a suitable mask/airline adapter was required. Horses supplied with air during the flight could be used to move equipment immediately after landing. Tests showed that horses need 4.6 liters of air per minute at 15,000 feet and 13.7 liters per minute at 30,000 feet to prevent physical stress.
 
The M6, adopted in 1951, was the final horse gas mask. This modification of the M4 mask included a brazed-on Air Force bayonet adapter to attach to the aircraft’s oxygen system. This allowed horses to be transported in unpressurized aircraft (usually propeller driven) at high altitudes without injuring or killing them from lack of oxygen as well as to protect them against chemical agents. The mask was adopted as the "Mask, Oxygen and Protective, Horse, M6." Within the next decade, horses and their associated equipment were deleted from the now mechanized and motorized Army.