Nail bind/nail prick

Foot problems are a common cause of lameness in the horse, accounting for 90% of all forelimb lameness problems. However, the importance of meticulous care of horses’ feet is often overlooked by owners. Neglected feet can develop many conditions which, if left untreated, can result in severe lameness with subsequent loss of use of your horse. Maintaining the hooves in good condition with the help of your farrier/hoof care practitioner is of primary importance in the overall health and welfare of your horse.

Nail bind is the term used when the nail of the horses shoe is placed too close to the sensitive laminae of the foot, resulting in pressure on the lamellae within the hoof capsule.
Nail prick on the other hand is the term used when the nail of the shoe is accidentally driven into the sensitive laminae of the foot.

Nail bind will usually result in inflammation and lameness in the affected foot, either immediately or a few days after shoeing. Nail prick is usually immediately evident following shoeing recognised by sudden-onset lameness. Both conditions create a tract through which infection may become established as well as the possibility of the development of tetanus.
Your horse will be sensitive to the application of hoof testers around the area of the offending nail.Your horse is likely to have an increased digital pulse in the affected  foot which can be felt on the outer and inner aspects of the fetlock (this is a useful technique and should be practised by all horse owners). The presence of this pulse indicates an inflammatory process is occurring within the hoof capsule. There may also be heat in the affected foot due to the presence of inflammation.
In advanced cases there may also be swelling of the lower limb and in severe or neglected cases there may be draining pus evident at the coronary band (the line of least resistance for infection to emerge if inadequate drainage has been achieved via the sole).

If you suspect your horse is suffering from either nail bind or nail prick, call your farrier or vet immediately. The shoe and nails should be removed by a professional as soon as possible. Horses suffering from nail bind should show some degree of improvement once the shoe is removed although the presence of bruising and/or infection will cause lameness to ensue.
The foot may need paring to establish drainage if infection is present. The sole should be cleaned and a warm/wet poultice applied to encourage darainage of infective material and contaminants from the nail hole. A dry poultice should be applied once all infection has been eliminated to harden the foot and your horse should be sound before being re-shod.
If  your horse is suffering from nail prick, the treatment will need to be more aggressive to treat any infection that may be present. The shoe should be removed, abscesses drained and the nail hole flushed, and a poultice should be applied to help draw out any infection. Your vet will check your horses vaccination status to ensure they are covered for tetanus. In severe cases, surgical debridement of necrotic tissue may be necessary.
Not until your horse is sound and free from infection can a shoe be re-applied.Getting the horse re-shod too early could exacerbate the problem.

Make sure you use a farrier that is fully qualified and registered with the Worshipful Company of Farriers; ask your vet or friends who they would recommend.
However, there are some cases which occur due to the conformation of the foot, making it difficult for your farrier to avoid the sensitive laminae, making these horses predisposed to this problem.
Although a rare occurrence, accidents do happen, especially if your horse is a fidget, but as long as your horse receives early diagnosis and treatment, he should suffer no long-term problems.
If your horse has poor hoof quality, ensure you are supplementing your horse with supplements that could help better hoof growth and quality, both of which will help your farrier achieve accurate nail placement. You can also help your farrier by training your horse to stand quietly while his feet are being handled.