White Line Disease in Horses- Causes & Treatment

Last Updated on January 22, 2022

If you have been in the horse community for any amount of time, you have probably heard someone reference white line disease. To learn about white line disease in horses, it is important to understand the basic anatomy of the hoof. A horse’s hoof can be looked at in layers- the outer hoof wall, hoof horn, and the laminae. You can learn more about hoof anatomy here. The white line is the light area between the hoof wall and where it joins the sole. Essentially, damage to this area makes it susceptible to fungal or bacterial invasions that will ultimately separate the hoof wall layers.

What is White Line Disease in Horses Caused By?

White line disease is something that typically affects horses that have a weakened hoof wall- it is considered opportunistic, and frequently a “perfect storm” scenario. The white line “widens”, which is the separation of the sole and hoof wall. Once widened, bacteria or fungi can easily be introduced and cause a progressive infection that will work its way up to the coronary band.

The most common causes of white line disease in horses are poor hoof structure or hoof imbalances. These problems can be natural or “man-made”, but any damage will create susceptibility. Other hoof issues that create a “stretching” of the white line or other structural problems can also lead to white line disease. Many horses are first diagnosed by a farrier during a trim, long before signs of lameness appear to the owner. When this infection reaches the coronary band, it can create a light powder that will be noticed during a trim or shoe reset.

White Line Disease Treatment

Treatment of white line disease is greatly dependent upon the severity and progression. If caught early enough, white line disease is fairly easy to manage. Horses may not even need time off if there is no severe damage to the hoof wall.

There are many products on the market to treat white line disease, such as CleanTrax. Your farrier will likely have a preferred product recommendation. Hooves are also soaked in a chlorine-based solution 1-2 times per week.

But regardless of severity, an infection should be treated immediately. Frequent trims will help with proper growth and monitoring. Some farriers will also recommend owners give a hoof supplement that contains biotin and amino acids. Good blood circulation and growth will assist in treatment.

CleanTrax Equine Hoof Cleanser


Although white line disease is an opportunistic problem, there are steps you can take to help prevent tearing or “stretching” of the hoof wall.

If it is not a complication from another hoof problem, proper hygiene and regular trimming are the best ways to combat white line disease. Some experts believe that extreme weather can also impact a hoof’s susceptibility to fungi.

White Line Disease Prevention

What to Remember

Early recognition is key in easily treating white line disease. However, successful treatment takes time as the hoof continues to grow and replace damaged areas. If you think your horse may have white line disease, it is important to consult your veterinarian or farrier for prompt treatment action.

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How serious is white line disease in horses?

Indeed, it is one of the most common hoof diseases in the world. According to the American Association of Equine Practitioners (AAEP), approximately 10% of all horses are affected by white line disease. White line disease is also one of the most expensive foot problems to treat. Hoof care professionals often spend hours and hundreds of dollars per horse to treat the disease.
The seriousness of this disease depends on several factors. Most importantly, the severity of the initial attack determines how long it takes for the horse to become lame. If white line disease is mild, the horse is likely to be lame for no more than a few weeks or months. However, if the initial attack is severe, the horse may be lame for years.

Is white line disease painful?

White line disease is a painful condition that lasts anywhere from a few weeks to several years. The horse may experience intense pain at night or in the early morning hours. This is often the time when the horse is most restless and the hoof is most painful.
The first sign of white line disease is a sudden onset of lameness with a swollen, red, painful hoof. The horse may also show signs of pain, fever, and an inability to eat or drink. In severe cases, white line disease may cause a horse to lose its appetite, become lethargic, and show signs of depression.
White line disease usually involves one or more hooves. Therefore, it is important that you examine each hoof carefully for any abnormal signs or symptoms. If you notice anything unusual about any of your horse’s hooves, please consult with your veterinarian or a hoof care professional immediately.

Does laminitis cause white line disease?

Laminitis and white line disease share many similarities, including a common genetic susceptibility. But they are two different conditions. The only way to tell them apart is to look at the X-ray. 
So, how do you differentiate between these two conditions? You have to look at the history of the horse. If you find out that they were stabled in a box stall and had a lot of work done on them, then they have a high probability of having laminitis. If they're on pasture and there's no other evidence of lameness, then that's a better indication that it's probably white line disease.

Is seedy toe the same as white line disease?

Seedy toe and white line disease are two completely different conditions. Seedy toe is a focal defect that affects the sole-wall junction while White line disease is a diffuse defect that affects the inner part of the hoof wall.
Seedy toe is a focal defect of the hoof wall that appears as a localized swelling of the wall just proximal to the coronary band. The lesion has a distinct pattern of progression and is usually located at the medial side of the wall. Seedy toe is not a true disease but rather a manifestation of an underlying cause. The most common cause of seedy toe is a hematoma or seroma resulting from a trauma to the area.