The Field Guard is easily accepted by most dogs because it is engineered for comfort. The correct size will allow enough room for the dog to open his mouth and pant, and for air to circulate all around the dog’s face.

1) Measure the Head Length

     • Dog should be looking straight ahead.


measure using string instead of tape measure

• Use a piece of string, then measure against a ruler.  The dog isn’t as likely to move his head under a thin string than a tape measure.

measure to base of skull

• Measure from the base of the skull, to the end of the nose.

 • Do not follow contour of snout.  Pink line is correct way to measure, dashed line is incorrect way.
 • For accuracy, measure 2 or 3 times.
 • PUPPY size is based on current head length.  Do not buy the next size up, it is 2″ longer & wider.

2) Choose Size

  14 – 18 cm     5½ – 7″ XXS
  18 – 21 cm      7 – 8¼” XS
  21 – 24 cm     8¼ – 9½” S
  24 – 29 cm     9½ – 11½” M
  29 – 34 cm     11½ – 13½” L
Extra Large is now available – 34 – 39 cm (13.5 – 15.5 inches) 

If your dog’s measurement is between sizes XXS & XS, XS & S choose the smaller size. S & M, M & L choose the larger size. If your dog is right on the borderline between sizes (18 cm XXS/XS – 21 cm XS/S – 24 cm S/M – 29 cm M/L) and they continually have their head on the ground e.g. sniffing, it may be wise to choose the smaller size. If the Field guard is always being dragged along the ground, it will wear out more quickly. Please note that in this instance, only choose the smaller size if your pup’s measurement is spot on the borderline i.e., 18,21,24 or 29 cm respectively.


Don’t forget about Positioning the Field Guard



The correct Size and Position are the key to your dogs comfort and acceptance of the Field Guard.

When the Field Guard is positioned correctly, it should tip downward, with the top of the Field Guard resting lightly on the top of the dog’s head and leaving ample space in front of the dog’s nose.

A common mistake people make is pulling the Field Guard back too far down the neck. When it is pulled back toward the collar, it tilts upwards and seats directly against the dog’s muzzle, and puts the panting room above his snout. This position irritates the dog’s nose and does not allow room to pant.

For a guide to important fit adjustments, download the latest OutFox Comfort Guide.