What is WLD White Line Disease?
White line disease (WLD) - decomposition of the white line - is caused by anaerobic bacteria and fungi. and is a widespread phenomenon, especially in our latitudes, alongside steel rot. Its consequences are hollow, loose walls, breaking nails, abscesses and foul-smelling rot in the sole, frog and corner strut areas.
Hoof areas affected
In bare hoofed horses, WLD occurs in the white line and in the corner strut area. In shod horses, it occurs in the white line under the shoe, mainly in the nail area. Especially when plastic or leather plates are used, but also with snowgrips and glued plastic shoes, no atmospheric oxygen can reach the horn. This provides an ideal environment for putrefactive pathogens to multiply.
Fig. 1: WLD under the still intact horn wall (dark areas in the nailing)
However, the use of hoof insoles, e.g. made of silicone, is often absolutely necessary for the treatment and prevention of damage to the hoof or joint area (e.g. laminitis, hoof roll inflammation, low heels). However, decay processes on the frog, white line, corner struts and sole that have already reached an advanced stage often call further use of the insoles into question.
How do I recognize white line disease in horses?
Symptoms and signs of white line disease
Black discoloration on the horn of the white line is always due to putrefactive pathogens. The soft horn of the white line is much more susceptible to bacteria and fungi, as the pathogens can easily decompose and digest the horn due to its soft and vulnerable structure; the horn of the wall and sole is much more stable in this respect.
Effects of white line disease on horses
Untreated, progressive white line disease can lead to severe wall eruptions and even hollow walls and the resulting lameness. The danger is that white line disease can initially only be seen from the sole side and it is not possible to see from the outside how far the damage actually extends upwards. If an incipient hollow wall or horn column is not recognized or played down, it can spread further and further under the apparently "intact" horn wall.
What are the causes of white line disease?
The cause of WLD is always horn-decomposing germs, symbioses of fungi and bacteria. One reason why so many horses are affected by white line disease is their husbandry: Horses originally lived in steppe-like regions with rather dry climatic conditions. There they moved around on huge surfaces - rotting of the horn can hardly occur in such an environment. When horses are kept in stables, especially in boxes, they are forced to step in their own excrement, even if they are kept clean. Bacteria and fungi lurk there, which, especially if ammonia has damaged the keratin protein in the horn, find a good breeding ground here.
Ammonia is produced particularly quickly in the warm season by the bacterial decomposition of urea in the horse's urine. The pungent-smelling gas is lighter than air, so it rises from the bedding and combines with moist air. It then sinks back into the bedding as ammonia. Ammonia and ammonia damage the keratin protein in the horn as well as the horse's skin and lungs. The now chemically damaged horn is the ideal breeding ground for bacteria and fungi. These decompose the horn, producing decomposition products such as hydrogen sulphide (rotten egg smell), which in turn can dissolve the horn. The result is a process that perpetuates itself like a vicious circle - even over long periods of drought.
How can white line disease be treated?
Procedure for white line disease treatment
First and foremost, a distinction must be made as to whether the horse is shod or barehoofed. A shod horse has the disadvantage that no light or air can get under the shoe. It is therefore just as difficult to get care products under the shod hoof.
Keralit Undercover - the hoof protection under shoes, plate, silicone insert
Our paste is suitable for shod horses Keralit Undercoverpaste, which is applied by the farrier into the cavities of the white line before nailing on, is ideal for treatment. The well-adhering hoof care paste has been specially developed to prevent horn decomposition processes in the white line, sole, corner bars and frog areas as well as in horn columns and hollow walls.
Fig. 4: Before nailing on the iron, the defective areas of the white line are cut out and filled undercover in the cavities
Keralit Undercover releases decay-inhibiting active substances throughout the entire shoeing period, especially if moisture gets under the shoe from the outside, e.g. by washing the hooves or from the bedding. When Keralit Undercover is used, the environment under the shoe or plate and the silicone is changed over the shoeing period so that decomposition processes caused by ammonia or microorganisms can no longer form. Foul-smelling putrefaction is prevented and the horn is stabilized.
Keralit Undercover is also often used for the treatment and prevention of horn decomposition in the frog area. It is particularly suitable for horses kept in open stables or paddocks, as it remains in the frog furrows for many days and adheres to the frog furrows even in wet weather. Daily treatment is therefore not necessary.
Keralit hoof strengthener - for barehoofed horses
With bare hooves you can easily reach the damaged areas of the white line. Here it makes sense to use the Keralit hoof strengthener from below and from the outside. This stabilizes the horn and counteracts horn decomposition processes.
Fig. 5: Application of Keralit Hoof Strengthener from the outside
Tips for treating white line disease
What to consider when treating WLD:
- Good stall hygiene, sufficient fresh air
- Regular scraping
- Little contact with water, no wet paddocks
- Do not grease damaged areas
- Do not wash with soap (alkaline pH value)
How do I prevent white line disease? Influence of the hoof shape
The hoof trimmer or farrier should always strive for a physiologically correct hoof shape with straight walls so that the hoof walls are bent outwards as little as possible in the lower hoof wall area (trumpet-shaped). Hoof walls that are bent outwards considerably promote white line disease, as the white line is already being stretched outwards at this stage, resulting in cracks and defects. To prevent WLD, it is advisable to ensure good stall hygiene, light, fresh air and plenty of exercise on wide runs. These are factors that all have a positive influence on the quality of the hooves.