Shoeing is necessary to protect the hooves of many hard-working horses, and nails are of course an important part of the process. Ideally, horseshoe nails enter the outer hoof wall, which lies adjacent to the "quick," or the sensitive laminae inside the hoof capsule. Occasionally, however, a nail is placed wrong and enters or presses against the sensitive tissue. An old term for this is called being "quicked." The horse's response to a prick can be subtle or dramatic. He might not react at all, or he might just tense his muscles or quiver slightly as he reacts to the pressure of a nail being driven close to the sensitive laminae. Or, he might suddenly jerk his foot away from the farrier's grasp and react more violently from pain of a nail gone wrong. A misplaced nail can lead to infection and result in a painful abscess.
What Does "Nail-Quicked" Mean?
Through training, a farrier learns how to position a horseshoe so each nail goes safely through the insensitive outer hoof wall. Driving the nail through this doesn't cause discomfort for the horse since the nail goes through the horn of the hoof, which is composed of keratin and contains no nerve endings, much like your fingernails.
A nail "quicks" the horse when it places pressure on the sensitive tissues of the hoof or invades the sensitive laminae. This layer of sensitive tissue lies on the inner side of the sole/wall junction (white line) and bonds the hoof capsule to the coffin bone.
Kirk Adkins of Vacaville, Calif., has been the staff farrier for the University of California, Davis, Veterinary Medical Teaching Hospital since 1986. A Certified Journeyman Farrier with the American Farrier's Association (AFA), he also teaches farrier science to UC Davis veterinary and animal science students. He says that there are two variations of "quicking:" A prick is actual penetration into an area that is composed of sensitive tissue. There also can be pressure on the sensitive laminae of the hoof wall if the nail is placed next to or through the white line. The pressure of the nail on this sensitive area combined with the movement of the horse causes constant irritation to the sensitive laminae, which leads to a painful infection seven to 10 days after shoeing. This is termed a "close" nail.
James Keith of Tucumcari, N.M., has been an AFA Certified Journeyman Farrier since 1982. He has twice earned the title of AFA Educator of the Year, and he has judged horseshoeing competitions in several countries. Having taught hundreds of farriers, he finds that quicking is a rare occurrence because, "In school, the farrier is taught anatomy, with an emphasis on the hoof anatomy," he says. "You learn where sensitive tissues are.
"Most horses will tell you when you start getting close," he says. "They tense up." Sometimes this might be hard to differentiate from a horse which just doesn't like nailing and continually flinches or snatches his feet from the farrier. Keith explained that usually in the case of a "quicked" horse, the farrier drives the nail, sees the horse's reaction, withdraws the nail, and drives it into the hoof correctly. The initial nail hole might create a small wound in the sensitive tissue that farriers call a "hot nail." Tenderness shows up four to five days after the shoeing, which is the amount of time necessary to form an infection and can last a variable amount of time, depending on the treatment and the extent of the injury.
A few horses might not respond to the pain. Keith says that some "have a high threshold of pain, and they will allow you to drive a nail into the sensitive area before you see a reaction." The first indication of a problem with such a horse might be lameness appearing a few days after shoeing once there is a painful infection.
Another reason a "quicked" horse might not appear sore is if he is quicked in both front or hind feet, since his gait might not be uneven. Adkins notes, "If you quick him in both front feet, you might not notice it. He will go away a little bit stiff. You won't notice any head nod, only a shortening of the stride. Over time he will get progressively worse."
Why Does a Horse Get Nail-Quicked?
Certain factors on both the horse's and the farrier's side can make it easier for a horse to get nail-quicked. These can include the shape and quality of hoof wall, the horse's behavior, the farrier's choice of shoes and nails, and his/her experience and expertise.
First, the thickness of the hoof wall dictates the amount of wall present in which to place nails. Thin walls are harder to nail into without hitting sensitive structures, and Keith blames excessive rasping for a thin hoof wall: "Most horses are not born with excessively thin hoof wall. Overdressing the hoof capsule (rasping it too much) up to the hairline will result in the horse acquiring a thin wall. You should only rasp halfway up."
Second, abnormal hoof shape can also be a cause of nail-quicking. If the hoof wall is broken away in places, or if there is weak or uneven hoof wall from a coronary band injury, the farrier has to adjust his nail placement to avoid these areas. Nailing higher on the hoof is sometimes necessary in such cases; this can help secure a shoe on the hoof longer, but increases a farrier's risk of driving a nail into or close to sensitive structures.
"Sometimes the structures in the hoof capsule aren't the way you think," Adkins adds. "If feet are distorted from bad conformation or improper shoeing over a long period of time, there can be bends in the hoof wall and the accompanying soft tissue, so you can hit the sensitive laminar corium and not be aware of it."
Another problem is that the horse can get himself nail-quicked by jerking his hooves away from the farrier while the farrier is nailing. Even the best farrier can find it difficult to precisely nail a moving target. Consider the level of accuracy implied by the old farrier joke, "I told you I'd shoe that horse! I nailed everything that flew by!" Thus, one way you can help prevent nail-quicking is to school your horse so that he stands quietly for trimming and shoeing.
Considerations for a farrier to avoid nail-quicking a horse are shoe and nail choice and nail placement. "The nail placement shouldn't be beyond the widest part of the foot. This allows for normal heel expansion and the hoof wall becomes thinner past this point as you approach the heels," says Stephen O'Grady, DVM, MRCVS, owner of Northern Virginia Equine in The Plains, Va.
"Nail holes in the shoe should not be too coarse," says Adkins. "Coarse and fine are terms used to describe the position of the nail hole from the outside edge of the shoe. Farther in from the outer edge of the shoe is 'coarse;' closer to the outside edge is 'fine.' "
The farrier must pay close attention to selecting and driving each nail. Not all nails are manufactured perfectly, and misshapen nails might not drive straight, says Doug Butler, PhD, AFA Certified Journeyman Farrier, Fellow of the Worshipful Company of Farriers, and writer of the popular farriery texts The Principles of Horseshoeing I and II.
"The white line is the guide," Keith says. "Fit the shoe so the nails enter the hoof wall in the outer edge of the white line, so a thin or thick wall is irrelevant."
"Considering the kind of physical margins we're working with, which are very small, it doesn't happen as often as we might think," Adkins adds. "Most farriers are very conscious of what they are doing."
What are the Effects?
"Usually there are little consequences, if the nail is withdrawn immediately and no infection is present," says Keith. "It's a small wound like a scrape on your hand, and usually heals up rapidly."
Adkins adds that the farrier can try to flush out a bleeding puncture; however, "Tissues are fresh and elastic, and close up fast." This makes it difficult for antiseptic to reach as far as the nail penetrated.
"If you see blood and pull the nail out right away, it could possibly be sore for a couple of days," Adkins continues. "If you leave it in, the horse can develop an abscess (a localized area of pus)."
Keith relates the effects of an abscess: "It normally results in layoff time, vet bills, and concern over the horse's well-being. I have seen in some cases a piece of the hoof wall lost, or even long-term foot deformities. That's rare, and due to neglectful treatment." He added that most of the abscess cases he has seen are caused by owners who try to shoe their own horses.
Pain and fear are other negative effects. "On a young horse, the pain of being quicked makes him distrustful of having his feet worked on in the future," says Keith.
How Do You Treat It?
Penetration into the laminar corium by a horseshoe nail should never be taken lightly, says O'Grady. "Treating a misplaced nail can be fairly simple or it can be complicated, requiring extensive treatment and lay-up time for the horse. If the horse is moving short or slightly lame immediately after shoeing, hoof testers can help locate the offending nail. At this stage, removal of the offending nail might be all that's necessary to resolve the problem. If blood is noted following removal of the nail, a suitable antiseptic solution should be applied.
"If more severe lameness is noted four to five days after shoeing, an 'infected nail' should be suspected," he continues. "Again, this is confirmed with hoof testers. The shoe should be removed and drainage should be established. The foot is then placed in a medicated poultice to enhance drainage. After one or two days, if the horse is sound, the poultice is removed and the foot is packed in gauze soaked in an antiseptic solution for another 24 hours. The shoe can then be replaced, taking care not to place a nail in or near the affected area."
If the horse begins to show a mild lameness five to seven days following shoeing and progressively gets worse, a "close" nail should be suspected. "These are often the hardest to treat, as the infection is not as localized and drainage is harder to establish," O'Grady continues. "If the first attempt at drainage is unsuccessful, a poultice should be applied. If after removing the poultice drainage is still not apparent, a small vertical notch extending to the white line can be cut in the outer hoof wall to approach the infection horizontally. Because of the diffuse nature of the infection, some of these cases will not resolve until the infection migrates dorsally and ruptures at the coronary band."
With any suspected or confirmed hoof infection from a nail, your veterinarian should administer tetanus toxoid as a preventive treatment against tetanus.
How Can Nail-Quicking Be Prevented?
As stated earlier, broken or thin hoof walls can increase a horse's chances of getting nail-quicked. Keep your horse's hoof walls healthy by making sure his diet gives him all the necessary nutrients for proper hoof growth, keeping him on a regular trimming or shoeing schedule, and keeping an eye on his feet so that any damage can be dealt with quickly. Doing these things will make sure that your horse grows solid hoof wall and always has balanced feet that are properly maintained.
Owners can also guard against quicking by employing a well-trained farrier who trims the hoof properly and uses appropriate shoes and the correct size nails. This expert can match the shoe design to the hoof, and make sure the shoe's nail holes are punched to correspond to the horse's hoof wall.
Accurate nailing is the crucial moment of shoeing. Adkins says, "To get down to it, if you don't nail the shoe on successfully, all your work is for naught. The job is not functional. One little fraction one way or the other, and you either lose the shoe or quick the horse."
Take care of your horse's feet so that your farrier has healthy hooves to work with, train him to stand calmly for shoeing, and employ a well-trained, trustworthy farrier to shoe your horse. If you do all these things, your horse's chances of suffering from a nail-quick are as low as they can get.
Quicked from Over-Trimming
Nail-quicking isn’t the only kind of quicking from which a horse can suffer—he can also be quicked and become lame if his sole is trimmed too close. "There’s a great tendency for inexperienced farriers (and owners) to think that you get more of your money’s worth by trimming more so you don’t have to trim so often," says Doug Butler, PhD, American Farrier’s Association Certified Journeyman Farrier, and Fellow of the Worshipful Company of Farriers, who wrote the popular farriery texts The Principles of Horseshoeing I and II. "This doesn’t leave enough protection for his foot—he may break over easier, but he won’t move as well. Generally, it happens to the pet horse or harness racehorse when people think a shorter foot helps him move faster."
The thinned sole does not offer enough protection for the hoof’s more sensitive inner structures, and lameness is the result. The worst problem of quicking from trimming too short is abscessing, whether from an infected deep cut or from a bruise. A quicked horse can bruise the sensitive solar corium or the bone, especially in a rocky area, because his protection from the sole is greatly decreased. The resulting abscess is usually infected with Clostridia bacteria, which produce gas that puts pressure on sensitive areas.
Treating a quicked horse depends a bit on the extent of the injury. If it’s severe, call your veterinarian. For minor wounds, treat conservatively. "If he’s bleeding, use a disinfectant and cover it with duct tape and a clean towel, gauze, or a disposable diaper to keep more infection from getting in," Butler suggests. "When it scars down a bit, cover it with a pad.
"If you cover a bleeding wound without treating it, it will often abscess," he continues. If it does abscess, Butler says it’s important to have a professional open up an abscess to drain. He uses magna paste or a 20% ichthammol solution to draw the infection and swelling out of a minor abscess.
"A pad is probably the best remedy to protect the tender foot until he grows more sole for protection," continues Butler. "But take the pads off as soon as you can so he doesn’t get dependent on them. You can give him Bute for a few days so he is comfortable enough to eat and move around, but the concern then is that he doesn’t hurt as much, so he might damage the thin sole more.
"You can also put turpentine or Venice turpentine on the normal or quicked sole to toughen it, but be careful not to spill it on skin because it will burn," he adds.—Christy West
About the Author
Award-winning writer Charlene Strickland lives in Bosque Farms, N.M. She has published 8 books and over 600 magazine articles, and is a member of the International Alliance of Equestrian Journalists.
POLL: Equine Acupuncture