White Line Disease in Horses

White Line Disease in Horses

Whinny’s Wisdoms

Springhill Equine Veterinary Clinic

Hey everyone, Whinny here! Since you’re a horse person, you’ve probably heard the old saying “No hoof, no horse”, and it will always ring true. Let’s chat today about a common hoof problem – White Line Disease. With the wet weather we’ve had lately, my Springhill vets have been seeing quite a few cases, and you may have even seen it without realizing!

Also called seedy toe, white line disease can start with just a little separation at the hoof wall. Maybe you’ve gone a little too long between trims and your horse’s hooves have gotten a bit too long. You notice a small gap between the outer hoof wall and the sole, and some dirt is packed in there. That can be how WLD starts, and at this early stage it can be pretty manageable, but it can get out of control before you know it. Let’s go into what white line disease is, what causes it, and what you can do about it.

What is White Line Disease?

Springhill Equine Veterinary Clinic

White line disease is basically an infection in your horse’s foot caused by bacteria and fungi getting into a gap in the hoof wall. The infection takes place in the tissue between the outer hoof wall and the sensitive inner tissues of the hoof. It doesn’t take any special evil organisms to cause this problem, it’s just the normal bacteria and fungi in your horse’s environment that are just waiting for the opportunity to find a nice place to set up shop. What they love is a dark, moist place, and a little space inside the hoof wall is their real estate dream. As the bacteria and fungi work their way into the hoof wall, they eat away at the tissue that should be keeping the hoof connected to the deeper structures. It’s a vicious cycle – once they access even further up inside the hoof and have a lovely dark, protected area, it gets much more difficult to clean them out. If you look at a foot with WLD, you’ll see a cavity between the outer hoof wall and the sole. You may be able to stick a hoof pick up in there and pick out some crumbly material that is the degraded hoof plus dirt, bacteria, and fungi.

You can find WLD on just one or two feet, or it can affect all four. In the early stages, your horse may not yet be sore, but as the tissue invasion becomes extensive, it can cause lameness. It can even progress to a very serious stage where the coffin bone loses connection to the hoof wall and begins to rotate (similar to, but different from, laminitis).

What Causes White Line Disease?

Like I said, bacteria and fungi are involved in WLD, but it’s not so simple as that, because the bacteria and fungi are always there in the environment, and not every hoof gets WLD. So how do they get into a foot?

It comes down to a separation that occurs in the hoof that gives the organisms a chance to invade – the bacteria and fungi are just there to take advantage of it. Why does that separation occur in the first place? Poor trimming or sometimes a conformational issue such as club foot can be the cause. A horse with chronic laminitis can also be at greater risk due to the loss of integrity of the hoof. Most commonly, a long toe or overgrown foot can distort the hoof and cause mechanical stress that leads to the hoof wall separating near the white line. Just another of the 10,000 reasons it’s important to stay on top of your horse’s hoof care and get him a quality trim at a regular interval.

Any age, sex, or breed of horse can be affected.  While it can occur in any climate, it’s more common in humid conditions (ahem, Florida anyone?) since wet footing can soften the hoof and allow the organisms easier entry into the tissues.

Springhill Equine Veterinary Clinic

How Do We Treat and Prevent White Line Disease?

First, we have to recognize the WLD. You’ll want to pay close attention to your horse’s feet when you’re picking them out. If you think there are any areas of separation, pockets of dirt, and crumbly hoof near the white line, talk to my doc and your farrier. If your horse wears shoes, it’s a little trickier to observe this area, so your farrier should take a good look when she removes the shoe to trim the foot. One of the best things you can do to prevent WLD is just to have your horse trimmed frequently (about every 5 weeks, depending on the horse) and to make sure the toes don’t become too long. A well-trimmed foot is much less likely to develop this problem. On top of that, pick your horse’s feet regularly and give them a chance to dry out. Admittedly, the drying part can be tricky during some times of the year.

If your horse does develop white line disease, my doc and your farrier should work together to develop a treatment plan. Unfortunately, just picking the cavity out and applying medications is unlikely to stop the progression. A very minor WLD may be able to be trimmed out by your farrier during a routine visit. Larger areas of separation will require additional treatment. My doc may need to take a radiograph to see how extensive the damage is within the foot. She’ll need to correct any abnormal forces on the foot (such as an overgrown toe) that are causing the separation. All the other treatment will not really be effective if the primary cause isn’t fixed.

Next, my doc has to stop those bacteria and fungus in their tracks. The most important part is to remember what those organisms love – a nice dark, moist space that can’t easily be cleaned out. So my doc takes the roof from over their head by performing a hoof wall resection! Those critters don’t stand a chance once their hiding place is exposed to light and air. My doc uses a hoof nipper or Dremel to remove the outer layer of hoof wall from over the cavity. The organisms are prevented from hiding up there, and the infected area is exposed for medications to be applied. Medical treatment is almost never useful unless the hoof wall over the infection is removed, so don’t waste your money on the various lotions and potions that make lofty claims.

Springhill Equine Veterinary Clinic

It can look a bit dramatic to see a bunch of hoof wall removed, but don’t worry, it’s actually only the outer part of the hoof that is already disconnected. So there’s no bleeding, and it’s not painful to the horse. It’s much better than leaving the bacteria and fungus to eat away at the hoof. If a lot of hoof wall must be removed, a shoe can be helpful to stabilize the foot until new hoof grows down.

Once the outer hoof wall is removed, you’ll need to keep the hoof clean. My doc likes to soak the hoof in CleanTrax once a week to disinfect the hoof. The new, healthy hoof wall will grow downwards from the coronary band and as long as you have corrected the primary problems, your horse should grow in a normal hoof!

Until next week,


P.S. Have you seen the latest videos over on my YouTube Channel? I just published one explaining how to treat thrush with copper sulfate crystals and a wax ring from the hardware store. Well, the humans did it, but I was involved! There’s tons of great how-to horse healthcare videos on my channel, as well as seminars, the Horse Girl series, and more. Give it a gander. It’s the best free veterinary resource around, except for our Podcast! Not to brag, but Straight from the Horse Doctor’s Mouth is the biggest equine podcast in the world. Now that I mention that, I think I need to step my game up with my blog! Help a girl out and subscribe, would you?

Whinny’s Wisdoms is the official blog of Whinny the Clinic Mouse at Springhill Equine Veterinary Clinic in Newberry, Florida. If you liked this blog, please subscribe below, and share it with your friends on social media! For more information, please call us at (352) 472-1620, visit our website at SpringhillEquine.com, or follow us on Facebook!

[jetpack_subscription_form title="Subscribe to Whinny's Wisdoms"]

More Adventures of the Horse Doctor's Husband
Tuesdays with Tony – Big Burly Men

Tuesdays with Tony – Big Burly Men

Last Wednesday evening was an atypical night for me. There was pizza, which is always a plus. But then about a half dozen big burly men with a bunch of tools showed up, pulling trailers with–get this–built-in furnaces! The docs called them Farriers. Turns out all you have to do is let them know there will be pizza, and they will come from far and wide. Beth brought in her horse, Princess Chubby Butt, to be the test subject. The docs learned how the farriers approach a problem foot, and the farriers learned why things are not always as they seem on X-rays. It was a great learning experience for everyone…OK, I’ll admit even I learned a thing or two.

It turns out if you ask 6 different farriers the same question, you get 6 different answers. In fact, it is widely accepted that if you ask 20 different farriers the same question, you will get 20 different answers. Luckily, we have a bunch of great farriers in our area, and although they may have different opinions about the right way to approach a problem, none of them are wrong. If your horse was experiencing a foot lameness, it used to be commonplace for your vet to blame your farrier, and for your farrier to blame your vet. But here at Springhill Equine we are trying to change that!

We see the vet, farrier, and horse owner as a team, and we try to come up with a solution by putting our heads together. Whether the problem is laminitis, club foot, navicular disease, arthritis, thrush, etc… you need a vet and farrier working together to get the foot going in the right direction. Farriers are often grateful to see what’s going on inside the foot with the aid of X-rays, and I know the docs are grateful to have somebody else in charge of hammering nails into the horse’s foot!

All in all, our first vet/farrier team building/brainstorming meeting (event name pending) was a huge success, and we hope to have more in the future. Oh, and Princess Chubby Butt is loving her fancy new shoes! If you are ever looking for a farrier, there is a long list of names in the desk that I like to sleep on, and we would be happy to find one to meet your horses’ needs.

Until next week,



farrier seminar 2Tony on farrier truckfarrier seminar 1

Tuesdays with Tony – White Line Disease

Tuesdays with Tony – White Line Disease

Tuesdays with Tony – White Line Disease

It seems there has been an awful lot of something called White Line around here lately.  I decided if there was going to be a bunch of it, I was going to learn about it.  As it happens, we had one of these horses come in to the Clinic to have his feet worked on, so I got first-hand experience.

This horse was seen by our Docs for a Wellness visit.  Small shameless plug for our Wellness Program:  It’s everything your horse needs for the year, it has built in discounts, there’s no emergency fee if you are on the Plan, there’s an awesome Kentucky Derby Party, and we take care of all the remembering of what needs to be done.  I really don’t understand why everyone who has a horse isn’t on one of our Wellness Plans. Anyway, back to what we were talking about… While there, they examined him for a right front lameness.  As with all lameness evaluations, the exam started at the foot.  This guy had a whole flap of hoof wall that wasn’t attached!  I have now learned this is a tell-tale sign that you’ve got White Line.  Yes, I did purposefully make that rhyme. It’s called a Cat-ch Phrase!

I started my adventure by assisting with x-ray set up.  I find there is no better resting place than atop a keyboard on a computer.  Turns out the humans don’t like it much, but we compromised and I was allowed to observe from an adjacent table as long as I agreed not to touch the x-ray computer.   They get sooo protective of their stuff.   We started our work on this horse with an x-ray of the front feet.  X-rays let our Docs and Shawn (the farrier) get an idea how much White Line Disease is present before they bring out the nippers, knives, and rasps.  The x-ray also shows if there are any other problems going on, such as founder.  I learned White Line can so compromise the structural integrity of the foot that founder starts.  Scary stuff.  I know from years of managing this Clinic that founder is very hard on horses.  Turns out this guy had a little bit of a change to the bones in his leg and foot.   The Docs and Shawn explained to me this wasn’t because of founder (looked the same to me) but was because this horse had something called a Club Foot.

white line with arrow

The x-rays led to a lively discussion on the causes of White Line Disease.  Apparently fungi and bacteria can be cultured from the nasty, chalky stuff that builds up under the loose hoof wall, but that’s not the heart of the problem.  Physics is the real problem.  The fungi and bacteria under there are just taking advantage of hoof wall that is being pulled away from the foot.  Almost always, that hoof wall is being pulled away because the hoof has bad conformation or it has been trimmed/shod poorly.  Usually the break-over is way too far in front of where it should be, which causes pull on the hoof wall with every step.  That pull opens up tiny cracks where bugs can grow.  The bugs then harm the hoof wall allowing it to open even more, which lets the bugs multiply. As you can see, it’s a vicious circle.  Check here for more information on the physics of feet: http://springhillequine.com/part-1-everything-you-ever-want-to-know-about-your-horses-feet

What’s a cat to do? Let the air in and fix the physics.  We’ll delegate the task out to fix the physics.  I’m not one for physics.  I lean more towards business management. Step one on White Line cases is to take off all that hoof wall that isn’t attached.  The bugs hate fresh air.  Take off the hoof wall, and they get more air than they can stand.  Off to bacteria/fungi heaven they go.  Next a shoe is put on that addresses any of those pesky physics problems.

white line Georgia

Voila! The worst of it is done.  At home the humans just have to make sure the foot stays clean.   They can do this by hosing the foot off, brushing with a wire brush (gently), and the occasional squirt of hydrogen peroxide (not too often, that is some powerful stuff).  The hardest part is time.  The horse will now need time for the hoof to grow out and heal.  Humans just don’t do patience well.  I recommend a good nap in a sunny spot.  It does wonders for my patience.

With all this talk about feet, I’m off to give myself a nice pedicure on the scratching post.  I think I will follow that with some patience practice.


Tony supervising Shawn