The Quick Muzzle is designed for average-snouted dog breeds, with tapered muzzles. To find a comfortable yet secure fit, the snout-circumference measurement is the most accurate way to determine muzzle size. (Because of the great size variations within a breed, weight is a less-reliable way to measure muzzle size.) Measure near end of snout. The muzzle should fit snugly around the end of the animalâ€s snout and throughout the muzzle body to be most effective.