To measure for size. go all the way around the snout just past the nostrils. this will be the snout size.
Selecting the right muzzle for your dog:
1. Use string (or a fabric tape measure) to measure your dog's snout, just behind the nose. The muzzle must not be tight.
2. Place your forefinger just under the string to ensure enough space for your dog to be comfortable-don't tighten the string, it should be free to move around the dog's nose.
3. Lay the string along a ruler to determine your dog's nose circumference. Find the corresponding size according to the size chart below-if it is not an exact match then take the nearest size.
4. Fit the selected muzzle on your dog. Check the fit by running your finger inside the nose band. Your dog must be able to pant and have free tongue movement. Better a little too loose than too tight! | 
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