Retired Veterinarian Jack Rife and his dog, Barklee, demonstrate how the pet oxygen masks works, Wednesday April, 19, 2011, outside Fire Station Five in Glendale. The Denver Fire Department receive 48 specially-designed animal oxygen kits from Invisible F

Retired Veterinarian Jack Rife and his dog, Barklee, demonstrate how the pet oxygen masks works, Wednesday April, 19, 2011, outside Fire Station Five in Glendale. The Denver Fire Department receive 48 specially-designed animal oxygen kits from Invisible Fence of Colorado. These masks are designed to fit a pet's snout and deliver oxygen. It is estimated that between 40,000 150,000 pets die in fires each year in the U.S. mostly to smoke inhalation. RJ Sangosti, The Denver Post (Photo By RJ Sangosti/The Denver Post via Getty Images)