ThinLine Flexible Filly Slow Feed Grazing Muzzle


Grazing Muzzle; lightweight, breathable, durable.


More like wearing a glove than a muzzle!

Horse grazing muzzles are a must for many horses but discomfort is not.

Try a natural grazing muzzle. ThinLine's research determined horses dislike muzzles because they cannot behave naturally in them. With the historical cage-like or bucket-like muzzles, horses are unable to engage in social activities like wither scratching or other playful interactions resulting in social and emotional health in horse herds.

This Flexibly Filly grazing horse muzzle is unlike the typical cage-like apparatus of the past. We designed this to be softer, lighter, and less behaviorally restrictive. Constructed of a durable and pliable material that radically improves the horses' feel. It is effective while also being soft on equine teeth and lips. The Flexible Filly Muzzle is well-ventilated and safe, rated to break just before your turnout halter. Additionally, the grazing hole size is adjustable, allowing you to offer the perfect grazing options.

-So light they won't even know they are wearing it.

-UV Protection for sensitive noses.

-Adjustable grazing hole size.

- Durability guarantee (6-month replacement warranty).

horse grazing muzzle

Available sizes. Order by halter size. Available in 2 grazing hole sizes. Holes may be enlarged with a pair of scissors.

Mini-Pony. Larger Miniature horses and up to large pony. Grazing Center holes. Full= 3cm, 1.2 inches or Restricted - 2.5cm.

Cob-Horse. Cob, Arabian, Quarter Horse or Horses on the smaller side. Grazing Center holes. Full = 3.3 cm, 1.32 inches or Restricted - 2.5cm.

Oversize-Draft. Larger horses, Draft, Warmblood and Oversize. Grazing Center holes. Full = 3.6cm, 1.44 inches or Restricted - 2.5cm.

*Halter not included, to purchase Custom Horse Halters for use with the Flexible Filly Muzzle available here.

What to know about Equine grazing muzzle center hole sizes.

Veterinary Recommendations for grazing muzzles hole sizes are as follows.

24/7 Full-time grazing in a muzzle; 3.5 to 4 cm.

Restricted grazing; for horses who require substantially less sugar intake; 2 to 2.5 cm.

The most common grazing hole size on the market is about 3cm and is not adjustable.

Full-Time Grazing in a Muzzle:

Recently, many horse owners prefer to leave their horse on pasture in a grazing muzzle full time - 24/7, which has created a demand for a larger grazing opening. With an industry-standard opening of under 3 cm, the roughage intake is often limited considerably. The digestion of a horse needs a minimum amount of dry matter to function properly and healthily. This minimum amount of dry matter is not achieved with a 24/7 restriction with an opening of 3 cm or less.

Owners should supplement feed in the form of hay, in order to guarantee the minimum intake in dry matter. Hay cannot be eaten, or only to a very limited extent, with an opening of under 3 cm, which means that the horse must actually be taken from the pasture, the muzzle taken off and then fed with hay and then back with a muzzle to the pasture.

The Full ThinLine Flexible Filly Grazing Muzzle has a larger opening than the average grazing muzzle, which made this muzzle unique. There are very few muzzles that are really suitable for 24/7 grazing.

Highly Restricted Grazing in a muzzle:

There is a lot of demand for a smaller hole for extremely limited grazing. Horses with laminitis, insulin resistance or those on lush fields need careful management and a 3 cm or greater grazing hole is too large to effectively protect them.

Therefore, ThinLine now offers muzzles with a 2.5cm grazing hole.

The Flexible filly equine grazing muzzle hole size is, you guessed it! Flexible!

The good news is, the flexible filly grazing muzzle limited hole size can be easily altered by horse owners for the perfect grazing opening. ThinLine now offers muzzles with a 2.5 cm hole. To create a larger hole simply mark your muzzle with a pen and use a pair of scissors to cut the size you need.

Because every horses's needs are different we offer you a fully customizable grazing hole for your equine muzzle. It is easy to have not only extraordinary comfort for your horse but also the perfect grazing hole size for all metabolic and environmental issues.


This 6-ounce grazing muzzle, made from one of the most durable polymers on the planet. It is fungal, mold, and UV resistant. It is safe, effective, and durable. There are no "off-gassing" materials so they are safe near the nostrils. Even if accidentally ingested the polymers pass USA food safety regulations.

The muzzle is ideal for slowing down speedy eaters, limiting grazing, and can help curb minor cribbing problems. The muzzle can also keep horses from chewing on leg wraps, wood, or blankets. It works extremely well with all automatic waterers and has UV protection which works much like sunscreen for those delicate noses.

Famous for Innovation in Shock Absorbing Equine Products - ThinLine hopes you enjoy the muzzle in addition to ThinLine's full line of tack.

Related Products.

The Flexible Filly Muzzle will not cause rub marks and is gentle on equine lips and teeth. We understand the halter you choose may rub so we designed a special halter available with or without wraps, made of ThinLine's anti-fungal, no rub ThinLine material.

Halter Designed for Grazing Muzzle.

Specially designed with manufactured slots to attache the muzzle, leaving nothing to rub your horse.

Halter Cover Liners.

Made with ThinLine, to prevent rubs ThinLine's halter covers may be added to any halter to offer clean, easy protection. No need to purchase zip tie covers when buying Halter Cover Liners.

Horse grazing muzzle

Quick Fitting Tips:

If your horse is attempting to eat out of the sides, first, remember, it takes them a while to learn how to do it!

If the problem persists:

a) Make sure your muzzle is not on the top hole, if you cannot raise the entire muzzle up a hole or two you might need a larger muzzle.

b) Make sure the fins between the front (or back) fin and the side (attached to the square ring) are evenly spaced. If you have the fins neighboring the center front or center rear too close to the center one the horse will be able to eat out of the sides rather than the grazing hole.

Video for Applying your new horse grazing muzzle click here.

Returns and Warranty Information.

Flexible Filly Horse Grazing Muzzles come with a full 6-month product replacement warranty and a 30-day product satisfaction refund.

  • Before you return, please email 2 photos of your horse wearing the muzzle. One grazing and one not grazing. Please send it to This way we can make sure it is fitting properly and offer guidance if needed. In ThinLine's experience, this muzzle works on every horse when owners have the correct size and it is fitted properly and secured. We are here to help you become accustomed to this new patented design.

Horse Grazing Muzzle, tie protector covers, halter cover kits, breakaway halter pictured above.

Horse grazing muzzle.

Download the Bridle2Fit Sizing guide to help make your custom-fitted bridle selections. 

Download PDF here