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Flexible Filly Slow Feed Grazing Muzzle

4.25 out of 5 based on 20 customer ratings
(20 customer reviews)


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

This Flexibly Filly grazing horse muzzle is unlike the typical heavy, hard, and “cage-like” apparatus of the past. We listened to horse owners just like you and designed this to be softer, lighter and less confining. Constructed of a durable and pliable material that radically improves comfort, it is also soft on equine teeth and lips. The Flexible Filly Muzzle is well-ventilated and safe, rated to break just before your turnout halter.  The grazing hole size is adjustable.

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 – 2cm.

Cob-Horse. Cob, Arabian, Quarter Horse or Horses on the smaller side. Grazing Center holes. Full = 3.3 cm, 1.32 inches or Restricted – 2cm.

Oversize-Draft. Larger horses, Draft, Warmblood and Oversize. Grazing Center holes. Full = 3.6cm, 1.44 inches or Restricted – 2cm.



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 2cm 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 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’ 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 our full line of tack.

Directions 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 our 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.


Related Products:

Halter Cover Kits.

Zip Tie Covers Accessories.


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 set of halter wraps (sold separately) made of our anti-fungal, no rub ThinLine material as well a cable tie covers. Available in Black or Brown, one size fits all. Use coupon code ThinLine for extra savings.

Can’t figure out how to use your muzzle? Check out these Flexible Filly Muzzle Instructions to help you use your slow feeding muzzle.


Horse grazing muzzle



Horse Grazing Muzzle, tie protector covers, halter cover kits, breakaway halter & visibility stickers pictured above.  Click on images to go-to products.

horse grazing muzzle


20 reviews for Flexible Filly Slow Feed Grazing Muzzle

    5 out of 5


    5 out of 5 stars! I love this grazing muzzle! It’s lightweight and durable. My horse loves it because it’s not bulky like his other one. He hates the other ones. They’re hard for him to breathe out of. Hoping a version for a miniature horse will be available soon!! My mini breaks grazing muzzles all the time.

  2. 5 out of 5


    Ok I don’t normally review or recommend products, but this muzzle is amazing!!!! Rilly is 19 years old and has Cushings and Insulin Resistance. She had a Lamanitic flare up last spring. I have never been able to get her to wear a grazing muzzle. She gets frustrated or maybe claustrophobic and takes it out on the other horses. She will chase them and bully them, or just run around spooking at everything with a muzzle on. I have tried so many brands, fits, an we have even made the holes bigger on some and it’s always a meltdown.

    I saw this new muzzle form ThinLine Global and had to try it. I am not going to lie, I was super skeptical. When I got it I was impressed as it was much lighter and more flexible than I expected. Today was the first time turning her out in it and there was NO ADJUTMENT period!! I am honestly in shock! She is just calmly grazing and enjoying turnout as if she isn’t wearing anything!!!

    I will keep you all posted on how it holds up but so far I am soooo happy! It is so light, breathable, and best part is it allows all of the dirt or weeds she doesn’t want to just fall though! She isn’t stressed or head-tossing (which she did constantly with basket muzzles)!

    5 out of 5

    (verified owner):

    I absolutely love the Flexible Filly Slow Feed Grazing Muzzle!!!!!! I’ve heard people say that it is just expensive plastic and complaints about the cost, but I will say this thing works great so it is worth it! Because of it my horse gets to spend spring and summer in the pasture instead of the pen. I like that you can choose your own breakaway halter to go with it. My horse does have some rub marks from his halter so I ordered the thinline halter guards to help with that and am looking forward to seeing how well they work. I will say I feel like the zip ties that come with the halter would not keep my horse from losing his muzzle so I chose to get some a little stronger. I know they have a reason for the zip ties that come with it, but I just didn’t feel they would be strong enough to keep my horse from losing his muzzle.
    One very nice thing is you are given a trial period that if it is not working for you, you can send it back.
    If you choose this muzzle I really hope it works as well for you as it has me. All the other muzzles out there are heavy or damage the horses teeth. This is lightweight and my horses teeth look good so far.
    Once again, this is a great muzzle and I can not say enough good things about it.

    1 out of 5


    Just looking at the photos it seems the plastic is over their nostrils in most photos. Not something I’d buy unless that feature was greatly modified.



      HI Frankie, thank you for your comment. We just posted photos which do a better job of showing how much breathability this muzzle has. Ventilation was one of our primary goals in the development. While we see it everyday and know how comfortable the horses are we are grateful you pointed out our images are not communicating this and we have (hopefully) done a better job on the product page. grazing muzzle ventilation images

    5 out of 5


    My super fat mini pony really needs this. PULEEEEASE make one in mini size soon.

    4 out of 5

    (verified owner):

    I love everything about this muzzle (the clear plastic, the breathing room, the adjustability, the durabiliyty) except one thing — the eating hole is too big (at least for some horses). It is noticeably bigger than the hole in the Best Friends muzzle. My equine nutritionist scored my boy an 8 out of 9 on the BCS scale (“fat”) and said that for him, the grazing hole is too big and lets him get too much grass. He wears the ThinLine muzzle 12 hours a day on pasture, and is on a sand dry lot with small amount of grass hay the remaining 12 hours a day. ThinLine, I hope you’ll consider offering the muzzle in more than one size opening for the overweight horse!

    1 out of 5


    I bought two of these grazing muzzles. I have a gelding who is half draft/ QH and is way over weight. I did buy him a draft size “Tough One” brand grazing muzzle but it seemed a bit too big and bulky and the next size down was way too small. So I kept seeing this particular add pop up on my FB page. So I thought I would give it a try. I bought two because there is free shipping if over $75.00…well the muzzle is $65.00… so since I have 2 horses…I would change over to this muzzle with my other horse and receive the free shipping. I receive the muzzles in the mail and do my best with the zip ties they send you. All looked good not tight to his muzzle but not too loose that it is floppy when grazing. He wore it for 4 days and I was so happy with the product. We went to a weekend baseball tournament and came home to the muzzle off, no zip ties on the halter…just the halter on him.
    So now I have to look for this clear plastic muzzle over 5 acres of pasture. No where to be found. We do not live close to any homes or roads. Someone did not come into the fence and cut it off of his halter. Have no idea where it is.
    So I get the other one that I bought and put that on him.( other horse can just use the other brand). Three days later I come down in the morning, he comes running in and no muzzle. No zip ties on his halter…no remnants of the plastic thinking it ripped off the halter. So off I go to look for it in the pasture. There it layed. No sign of any zip ties still on it. I am just happy I found this one.
    So I give up. I now have only one filly grazing muzzle that lays on the shelf. I am out of $130.00 and I just put the other brand back on him. At least if this one comes off…it is much easier to find in the pasture. The only reason I give it one star is because I was impressed that the holes and the entire piece never ripped. It is good plastic. Hope all of you have a better outcome than I did.



      I am sorry your horse has broken the zip ties and lost his muzzle. That is a hassle for sure. Our priorities are safety of the horse first, safety of the expensive polymer the muzzle is made from second and relief from hassles third. As to your post. We are a small company (4 employees) so we try to manage things such as product review posts a few times a week as they are not as important as say, returning emails and helping customers directly. The aggressiveness of 2 product reviews and multiple posts tells me you probably would like a little more personal attention, which we are happy to provide. A request for a replacement to would have done the trick. Your muzzles are under warranty. We will replace the lost one and we can send you heavier duty zip ties to try on both muzzles. Only a small portion of horses need the heavier zip ties so we prefer to make safety of the horse our first priority. As to the color, the clear muzzle allows owners to see what is inside the muzzle so they can better manage the health of their pasture horses. And the UV protection is quite good so there are no worries about the sun. We do offer bright pink stickers but I personally know several people who just place some bright colored duct tape on the muzzle if they are turning out in a large pasture for the first few days. I have no idea why your horse is being a challenge with keeping the muzzle on. 98% of horses are just fine with the provided zip ties. Still, we are very confident if we ship you the new muzzle and the new zip ties you and your horses will be very happy. All you need to do is send the email to with replacement in the subject line. Then we are out the cash, not you.

    1 out of 5


    I placed a review on here and it was not published. Was it because I only gave it 1 star? Not sure but I would sure like to know.



      Not at all. We are very happy to hear any and all feedback. We are a small innovative company and when we put new designs on the market there are always a few people who allow us the opportunity to make the products better. The review was not immediately posted because the four of us are quite busy during the day so we tend to review products posts about twice a week. Please know, if you call 888-401-9101 we are always here to speak to you personally and instantly.

    5 out of 5

    (verified owner):

    My Welsh Pony loves this muzzle. Always head tossed with the other heavy styles. I can walk him out to the pasture in this one with
    out having to worry about his head tossing and hitting me. I do need to order the small pad covers to go over the two ties at the nose of his halter as he is getting rubbed just in those two spots.

    5 out of 5

    (verified owner):

    I’m not much to review but I feel like sharing how this has worked for us. It has been wonderful. Three things that I can say have been great for us..1.. is he doesn’t throw his head when putting it on everyday. 2.. Very light weight for all day wearing. 3… He can get into our automatic waterer. It’s a little pricey. Hopefully it last a while but I would highly recommend this muzzle.

    4 out of 5


    I have 2 of these muzzles now. The first one I bought in the beginning of June and I received the second one 2 days ago. My air ferns are out on pasture at night and in stalls during the day. Their old muzzles, they used to chew the hole in the bottom bigger to the point that they were useless. So far, I am very impressed with how the Thinline is holding up. It is lightweight and seems quite comfortable.

    I do have a couple suggestions that I feel would improve these muzzles, IMHO. I think the hole in the bottom could be smaller. I would also be happier if they came on their own halter instead of having to attach it myself. The first one, I put on a regular halter and even though I ran the zip ties in between the two layers of the halter, it still caused a rub on my pony’s nose overnight. After that I attached it to my old grazing muzzle and just cut the old basket out. The old muzzle had a nice wide (like 3″) noseband with padding and had adjustable cheeks, throat and crown. I did the same with the other muzzle I just got for my other horse. So far, no one has had any rubs or escaped from their muzzle, so I am quite happy. Thank you for your quality products!

    5 out of 5

    (verified owner):

    I absolutely love these muzzles. I’ve tried many different kind on all 5 of my horses. They are all very different sized muzzles and jaw bones and I have two who always get rubbed in any other type of muzzle I’ve tried.
    Bought these for two and loved how they looked I bout more for my other guys. These muzzles are literally worn 24/7 except when feed there grain. They have healed the sores the other muzzles have caused and they all do really well in them. The color has faded and turned a thick yellow color fairly quickly but overall still does just as well of a job. They are beyond my expectations. Well worth the investment. I’ve had two horses (at different times) get “hung up” and only had to replace two or three zip ties and it was good to go again. No issues, didn’t rip the holes. Would recommend these to everyone.

    5 out of 5


    This muzzle has been a lifesaver. My horse is able to go out with the rest of the herd and is no longer trapped in the dry lot! He’s happy and so am I!

    5 out of 5


    This muzzle is THE BEST by far on the market I have tried them all living in the KY blue grass. The muzzle is light weight and airy. It does NOT rub even while being worn 24/7 ( all other muzzle brands rubbed raw spots w/ continuous wear). The horses don’t even try to remove them and seem to forget they’re on. It has also ( as expected) kept my fattest grass gorger’s weight under control while turned out on lush fields 24/7.
    Finally!!! A muzzle that I don’t feel bad about keeping on my horses and that the horses will keep on.

    5 out of 5

    (verified owner):

    This is the best muzzle out there – lightweight, durable, and my mare can breathe just fine. You can adjust it to ensure it does not touch their nose or mouth in anyway. My mare has gotten it off twice – knocked the low profile zip ties right off to where it is flapping all over the place. Easy to fix with the extra that come with the muzzle, but I have had to purchase more. The muzzle itself has not broken in any way and I would highly recommend it. Now need it in yearling/pony size for my Welsh/TB pony named Diablo! 🙂

    5 out of 5

    (verified owner):

    Love this muzzle !!! My horse is so content with it on,you think she didn’t have one on !!! Just ordered the Mini for my shetland I know she will LOVE getting rid of her old muzzle . Thank you Thinline for developing this great product .

    5 out of 5

    (verified owner):

    My Halflinger and I love this product! Have bought and replaced many muzzles over the years until a friend suggested trying this muzzle. Easy to put together and adjust – only needed to replace 1 tie all year. Would highly recommend this product!

    5 out of 5

    (verified owner):

    Love this muzzle. My girl doesn’t seem to mind it at all. I did have it a bit loose and she figure out how to eat around it, but that was on me. She wore it all summer and had no problems at all. She did break one of flaps that hold it in place right at the end of the summer but I think I can work around it next year.

    5 out of 5


    I LOVE THIS MUZZLE! We use them on a few of our police horses with laminitis and it has been a life saver. We have tried soo many muzzles and they all either broke quickly or the horses would literally run away from us because they hated them so much. We also had many issues with rubs in their faces no matter what we tried. This muzzle has been phenomenal! Has not broken, stays on, breathable and light, causes NO rubs, AND the horses don’t mind them! They never run away from us when we are coming to put them on. Best muzzle, HANDS DOWN! Our guys are hard on them and the only thing we have had to do is replace the zip ties, which we just get from Home Depot.

    4 out of 5


    This is by far the best muzzle I’ve purchased and believe me, I’ve probably purchased them all. The only thing I’m a bit disappointed in is when I originally purchased the muzzle I contacted customer service and they told me the muzzle generally last about a year. It seems my horse goes through one every six months.

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Questions and answers of the customers

  1. A Thank you for your question! The wear can vary depending on the particular horse and how they graze. These muzzles were in product testing for 3 years and lasted all three seasons on most of the test horses with very little wear. We offer a 30-day satisfaction guarantee and a 6-month warranty on the Flexible Filly Grazing Muzzles, so please feel free to give it a try!
  2. A Thank you for your question! The muzzle is made wholly in the US and we ship from North Carolina.
  3. A Thank you for your question! The medium size muzzle will be a good fit for your horse.
  4. A Thank you for your question! The muzzle is designed to be worn with a breakaway halter while grazing. It might be possible to use it with your bridle while riding, but please be mindful that it is not covered under warranty for this usage and of the possibility that it may interfere with your bit while riding.
  5. A Thank you for your question! The Flexible Filly Grazing Muzzle comes with everything you need: clear instructions, the muzzle, temporary twist ties for fitting, and two sets of zip ties for attaching to your turnout halter!
  6. A Thank you for your question! The Flexible Filly Muzzle is flexible enough to fit into automatic waterers. We offer a 30-day satisfaction guarantee, so please feel free to give it a try!
  7. A Thank you for your question! The hole is about 1 1/2" across.
  8. A Thank you for your question! Give the large a try! It fits a wide size range and has a 30-day satisfaction guarantee.
  9. A Thank you for your question! The Medium size (24") Flexible Filly Muzzle is the best choice for ponies, cob size, and full size horses that wear their halters on the smallest holes.
  10. A Thank you for your question! The high-performance muzzle material is UV resistant. It doesn't react to the sun and also offers some protection for delicate noses.