White Line Disease: What it looks like and how to avoid

Right Front (RF) Lateral view.

RF Medial view crack to left of toe

RF Oblique  WLD at heel/quarters

RF Solar WLD at quarters to heel

White line disease (WLD) is not a disease but a fungus that can be treated and grown out. It needs to be addressed by both owner and trimmer as a team. The photos of the above hoof show WLD in the right front hoof. This horse has had a crack. That, along with environment and diet factors, allowed the fungus to enter the hoof laminae and take hold.

How to prevent WLD and create a healthy hoof.

• Nutrition: A balanced diet with plenty of good quality grass hay along with a Vit./mineral supplement balanced for your area. The PNW soil is low in selenium, the hays are high in iron and manganese and deficient in copper, zinc and lysine. High levels of iron block the absorption of copper.  Signs that your horse is nutritionally deficient are poor hoof quality, a dull hair coat and an overall lack of condition. The best way to have your nutrition program balanced is to have your hay tested. If your hay comes from multiple sources feed a supplement that balances the minerals deficient in your location. Mineral blocks are very high in iron and should be removed and replaced with a white salt block or loose salt.

• Environment:  Too wet, mud, too much rich grass, over grazed stressed pastures, lack of movement, all key factors that can lead to WLD and other problems with your horse's hooves. Keeping it all in controlled BALANCE and being aware of your horse's condition will help better your horse's body condition and hooves.

• Hoof care - Regular (4-6 weeks) correct trims, cleaning the hooves, diligent treatment of thrush/cracks/WLD and booting when needed.

Over time, if any of these factors are deficient or neglected, they will start to show in the horses hooves, their hair and their overall condition. The trim is a small but important factor in hoof care, the other key factors need to be provided by the owner. Nutrition, Environment and Hoof Care, keeping all in the correct balance will lead to healthy hooves.


Same horse, left front hoof, seam is a former crack, no WLD.

Left Front (LF) lateral

LF oblique