Field Guard sizes to fit every dog

Good Fit ⇒ Comfort ⇒ Easy Acceptance!

A well fit Field Guard is easily accepted by most dogs because it is engineered for comfort. The correct size allows room for the dog to open his mouth and pant, and for air circulation around the face that is necessary for cooling. If you want the best fit for your dog use these measuring instructions for exact sizing.

Updates to 'O' Sizes

Before March 2022, dogs with furry faces, extra long ears, or a blocky heads required an “O” size to allow space for necessary air circulation and cooling.  All other dogs were able to utilize our regular size. With the announcement of our new sizes, we have eliminated the 'O' size. 

The chart below is the New Size Guide Chart for all sizes in stock.

Note that PUPPY size is and has always been based on current head length.

Size Chart

Measure your dog for correct sizing.  Breed examples are just a rough guideline.

If your dog’s measurement is on the borderline between sizes….
     XXS&XS, XS&S choose the smaller size
     S&M, M&L, L&XL choose the larger size

Need Help Choosing a Size?
For additional assistance, email us at Please include head length, weight, and a photo of your dog.

Adjusting for Fit
The correct fit is as important as size for your dogs comfort and acceptance of the Field Guard.  Download the OutFox Comfort Guide  for how to create the best fit for your dog.