There are two different OutFox® Field Guard sizes:  one for dogs with regular head shapes & one for dogs with wide or furry heads, long ears, or short snouts. 
(Pointy-eared dogs do fine in regular sized Field Guards)

How To Measure


Length:  Measure at the top of the head, from the skull base to the end of the snout.


Circumference:  Measure loosely around the largest part of the head: go gently over the ears.  If the ears stand up, don’t measure up and over the ears.


In the charts below, breed examples are only a rough guideline.  

Please always measure your dog for exact sizing.

 Note: For breeds with wide or furry heads, or those with very long ears (like Basset Hound) sizing is based on head length.  
For flat snout dogs, (Boston Terrier/Pug/etc.) sizing is based on circumference. 

(If your dog measures on the borderline between sizes, choose the smaller size).

Regular Sizing

Dog Type Head Length Field Guard Size Breed Examples
XXS 5-6.5″ XXS Chihuahua, Miniature Dachshund
(custom order for dogs under 8 lbs)
XS_spaniel 6.5-8.25″ XS Cairn Terrier,  Jack Russell,
Norwich Terrier, Whippet
S_beagle 8.25-9.5″ S Beagle, Border Collie,
Brittany Spaniel, Jack Russell, Sheltie,
M_icon2 9.5-11″ M Australian Shepherd, Vizsla, Labrador,
Greyhound, Wheaton Terrier
11-13.5″ L Doberman, German Shepherd,
over 13.5″  CUSTOM ORDER  for head lengths over 13.5″
or head circumference over 25″

Wide Head/Short Snout Sizing

Dog Type Head Circumference Field Guard Size Breed Examples Head Length
XS-short 15-17″ XS-Short Boston Terrier, Pug, Shih Tzu,
King Charles Spaniel
S-Short 17-19″ S-Short Cavalier King Charles Spaniel,
French Bulldog
M_Short 19-22″ M-Short Boxer, Small English Bulldog, Pit Bull 8.25-9.5″
L_Short 22-25″ L-Short Basset Hound, English Bulldog,
Labradoodle (with long hair),
Small Rottweiler,

(Wide/Short sizing is named simply, “Short” in the above chart)
If you have any questions or concerns about choosing the right size, feel free to email before you place your order.