ThinLine Flexible Filly Grazing Muzzle FAQ

A horse’s favorite grazing muzzle.

ThinLine Grazing Muzzle
  • What size does my horse need?  

Choose your muzzle size based on your horse’s typical halter size. e.g., If your horse wears a cob halter, you’ll order a cob/horse size muzzle.

  • Which grazing hole size should I choose? 

2.5+ cm- Vet recommended for horses requiring minimal forage intake due to existing health conditions.

3.5+ cm – Vet recommended for horses requiring general weight management and as a preventative to founder and other health issues.

Grass blade sizes can also vary by variety and location, affecting the recommendations about grazing hole sizes. 



  • How do I attach it to the halter?
    • To find the correct holes on the muzzle, orient the side fins with the triangle cutouts to your square side halter rings. 
    • The muzzle can be fitted so that it’s between 1 finger’s width away from the lips to almost touching the lips. 
    • The side fins are fitted 2 holes shorter than the front and back fins.
    • Use the temporary fitting ties to attach the side fins and all the others where they naturally lay around the front and the back of the noseband.
    • Hand graze with the fitting ties to check the fit. You’re good to go if your horse looks comfortable and can eat out of the center hole!
    • Once you’ve decided on the holes you’ll be using, the fin goes on the outside of the noseband, and the zip ties wrap around, using the fins’ holes above and below the noseband to secure.
    • Be sure to secure the zip ties tightly and trim the excess length of the zip tie.
    • Trim away any extra fin length that extends over the noseband, rounding off the corners.


  • How do I enlarge the hole?
    • To enlarge your grazing hole, trace a circle around the original hole for the desired size, then cut around the circle with utility scissors.
  • Can I use any turnout halter?
    • Yes! ThinLine muzzles work with any breakaway halter. Thinline’s specially designed breakaway halter has custom zip tie keepers built into the noseband for easy fitting and attaching.
  • Can my horse eat hay?
    • Yes!
  • Will it work with an automatic waterer?
    • Absolutely! It’s so flexible that it works well with most automatic waterers. Check that your horse is drinking well before leaving them.
  • Does this work for horses on pasture 24/7?
    • Yes! Check your horse regularly to ensure all is well, and monitor weight. If your pasture horse’s grazing is more restricted than needed, you can easily enlarge the grazing hole. 
  • Will the Flexible Filly Grazing Muzzle help prevent cribbing?
    • While mainly designed to reduce forage intake, it has also helped some minor cases of cribbing.
  • My horse has never worn a muzzle. Any tips?
    • During fitting and when putting it on for turnout, feed a little treat or a handful of grass through the grazing hole to help encourage a positive response. It also proves to them that they’re still able to eat!

What can I do if my horse is eating out of the side?

  • Lower your halter’s noseband and raise the muzzle, so it’s attached using the lower holes.
  • It’s ok for the muzzle to be close or even lightly touching your horse’s lips. It will drop further away from the face when your horse’s head is down grazing.
  • Check that the side fins with triangle cutouts are attached 1-2 holes shorter than the rest.
  • The front and back fins should all be on the same holes, 1-2 holes longer than the side fins.
  • Still able to eat out of the side? Please get in touch with us. Your muzzle may need to be exchanged for a smaller size.

Top Features:

  • So lightweight, airy, and flexible, they almost won’t know they’re wearing it!
  • Sizing for all equines – minis to drafts, donkeys and mules too!
  • Adjustable grazing hole size
  • Veterinarian recommended
  • Very gentle on teeth, lips, and skin. Irreversible teeth wear is one of the hidden dangers of other muzzles.
  • Safety first system! It’s all breakaway and is rated so that the zip ties break first, then the muzzle material, and finally the halter’s breakaway piece.
  • Works with any breakaway halter or use the ThinLine Halter for a perfect and easy fit.
  • UV protection for sensitive noses
  • Durability guaranteed- 6-month full replacement warranty.
  • Encourages natural herd behavior and promotes social and emotional health during turnout while reducing grass intake.


Accessories that work with the Flexible Filly Grazing Muzzles: 

ThinLine Breakaway Halter

ThinLine Halter Padding

ThinLine Cheek Guards

Purchase the best grazing muzzle here:


ThinLine Flexible Filly Grazing Muzzle Warranty 

90 day limited warranty – One time replacement


  • ThinLine zip ties must be used.

  •  A break away halter must be used. 

  • Photos and proof of purchase required. 

  • Any modifications or issues caused by normal wear and tear will void warranty. 


Please note: Your horse’s safety is paramount. There are safety breakpoints in place to prevent the risk of injury to your horse while wearing the grazing muzzle and breakaway halter. 


Normal wear and tear included but not limited to: 

  • Discoloration, teeth marks/grazing hole wear caused by exuberant grazers or pasture mates.

  • Damage caused by a safety feature working resulting in a torn fin. 


30 day satisfaction guarantee:  

Should you decide not to keep your grazing muzzle, you are responsible for all return shipping costs, but 100% of your purchase price will be refunded with proof of purchase.  Please be sure to clean products to the best of your ability and make sure items are completely dry before packaging for return. Any modifications made to muzzles will void this guarantee.