What is White Line Disease?
A fungal infection in the hoof of a horse, white line disease will begin either as a splitting of the wall of a horse’s hoof at the white line (inner layer that is soft and fibrous) or an infection surrounding the nail holes. Due to the infection, either a fungus or bacteria (or both) infiltrate the hoof wall and the wall will break down; as the infection continues, the crack in the hoof will get bigger and a poor smelling substance will appear in the crack. The growing crack will weaken the attachment of the inner and outer walls of the hoof. Upon significant progression of the disease, it will be hard to shoe the horse and keep his shoes on, which may lead the horse to be lame. The disease is also known as stall rot, hollow foot, wall thrush and seedy toe.
White line disease occurs when the hoof wall becomes separated or cracked, usually due to unusual stress on the wall; within these cracks, bacteria and fungi are often found.
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Symptoms of White Line Disease in Horses
Should your horse develop white line disease, when looking at his hoof your veterinarian or farrier will notice that the hoof wall is separated in the non-pigmented part in the mid layer of the hoof capsule. A small area may be seen along the hoof wall that appears to be powdery and the soles may be tender. Other possible signs include warmth in your horse’s foot, a slowing down of the growth of the hoof wall, and your horse showing discomfort when putting weight on his hoof. Often, when tapping on the outside of the wall at the toe, you may hear a hollow sound where the hoof is affected. In severe cases, lameness may be seen.
- White line disease can happen in one or more of your horse’s hoofs.
- Separation of the hoof wall
- Powder-like substance along hoof wall
- Warmth in the foot
- Lameness (severe cases)
White line disease may be a primary condition or a may occur as a result of a secondary complication to another disorder of the hoof, like club feet. In severe cases, there may be a loss of support of the distal phalanx, causing displacement and leading to possible lameness.
Causes of White Line Disease in Horses
The following factors can lead to white line disease in your horse:
- Residing in a damp or humid environment
- Experiencing stress after having had laminitis
- Injury to his hoof
- Particularly long toes which can lead to stress in the area where the hoof wall meets the sole of your horse’s foot
- Dirty bedding or unclean living quarters
- Lack of nutrition
It is possible that significantly wet or dry conditions will increase the likelihood of the fungi infecting the hoof of your horse. In such conditions, it is even more imperative that good hoof hygiene be practiced.
The disease rarely happens in horses that are unshod and on pasture. It is most seen in horses that are shod but have minimal exercise each day, reside in damp stalls and experience situations where they go from wet to dry conditions, as this increases the opportunity for bacteria, yeast or fungus to invade the hoof wall.
Diagnosis of White Line Disease in Horses
If you are concerned that your horse has white line disease, you will want to contact either your veterinarian or farrier. In order for white line disease to be diagnosed, your horse will undergo a complete physical exam as well as radiographs to determine the degree of separation of the hoof wall along with whether there is any displacement of the distal phalanx.
Treatment of White Line Disease in Horses
Corrective trimming is important in order to remove any abnormal stress on the hoof wall. Afterward, debridement of the separated hoof wall should occur. When debridement is done properly, in many cases there is no need for antiseptic treatment. Topical treatment with tincture of iodine is often used daily for a minimum of one week. There are equine foot formulas with chlorine dioxide that can also be used and your horse’s feet should be kept as dry as possible. Corrective shoes are important to provide necessary support to the foot and remove stress from it. When white line diseased is handled in its early stages it will lead to very few issues. When left untreated it can lead to damage of the hoof wall and ultimately lead to lameness in your horse.
Recovery of White Line Disease in Horses
It is important to ensure that your horse has good hoof hygiene; this includes picking his feet every day. By regularly checking his hoofs you can notice early signs of white line disease and begin controlling the issue. While treatment may take a lot of time (the hoof wall has to grow out and take the place of the damaged portion), it is important the condition be treated so that it does not worsen.