These tiny parasites feed on your horse’s blood and can pass along several pathogens as they do. Here’s what you need to know to protect your horse from ticks.

- By Kathryn Duncan, DVM, PhD, and Kellee D. Sundstrom, MS

You’ll hear many terms for hoof cracks---sand cracks, weather cracks, grass cracks, etc.---but the most basic way to describe these defects is according to their location and direction. These indicators also offer clues to the origin and severity of the problem.

Vertical cracks, which run perpendicu­lar to the ground, are the most common. The reason has to do with the anatomy of the hoof wall itself. Like human fingernail­s, hoof wall is composed mainly of a protein called keratin, which forms tubules---structures that look like densely packed drinking straws. These tubules run vertically down the hoof, from the coronary band to the ground, and give the hoof much of its structural strength, like the rebar in concrete. Weaknesses that allow cracks to form are much more likely to develop between the parallel tubules than across them.

Location determines how serious these cracks are likely to be. Those that originate at the bottom edge of the hoof wall and climb upward are typically just a cosmetic concern that is likely to be eliminated at the next trimming. Vertical cracks that originate at the coronary band and grow downward are more worrisome, especially if they’re deep, because disruption at the coronary band affects the production of new, healthy horn.

Vertical cracks are further defined by where they appear on the hoof wall:

• Toe cracks occur in the front third of the hoof. Because the hoof wall is thickest and strongest at the front of the hoof, serious cracks at the toe are less likely to be caused by external injuries. However, abscesses, bruises and other internal issues that loosen the bond between the hoof wall and the underlying connective tissues can create weakness in the structure that may result in a deep crack.

Chronic toe cracks can also occur in horses with conformati­on issues that increase stresses on the front of the hoof. “Abnormally high or low coffin bone angles cause toe cracks,” says Steve Kraus, BS, CJF, head farrier of the Cornell University College of Veterinary Medicine. “Often, long pasterns and low-angled heels cause the front of the hoof to extend too far ahead of the leg.” As the horse walks, the breakover places extreme leverage on the inside of the hoof wall, which can bend the wall inward and cause cracks.

“When a hoof has an

abnormally high coffin bone angle, the hoof will land toe first, which also puts excessive force on the inner hoof wall, creating the crack,” says Kraus.

• Quarter cracks develop along the side of the hoof; these tend to cause more trouble than toe cracks because the wall is thinner and must flex as the hoof bears weight. Any cracks in the side of the hoof will be less stable and are more likely to lead to lameness.

Quarter cracks are often caused by conformati­on defects in the legs, such as legs that toe out. “When the hoof is out of balance it creates too much pressure on one side of the capsule,” says Tommy Boudreau, a farrier in Mineral Wells, Texas. “This will push into the coronary band and cause it to jam up. With all the extra pressure in one spot on that side of the foot it can make it break out and crack.”

These conformati­on faults tend to create chronic cracks in a predicable location, says Kraus: “If you drop a plumb line down from the front of the horse’s shoulder, it will point to the crack.”

An underrun heel and long toe also places stresses on the quarters with each step. The prying forces will separate the hoof wall at the bottom first, and the crack will grow upward. Its edges will spread apart as the horse bears weight.

• Heel cracks occur at the rear of the hoof, below the heel bulbs. Like quarter cracks, these, too, are likely to cause lameness. A shoe that shifts to the side or is too small to support the entire heel to begin with is a common cause of a heel crack. The portion of the heel that overhangs the end of the shoe may split vertically; the edges of the crack will slide up and down past each other with each step.

Overstrike­s, when a horse hits the coronary band of a front foot while overreachi­ng from behind, are another common cause of both heel and quarter cracks. “A blow to the coronary band causes a bruise and damage to those tissues,” says Boudreau. “If there’s not enough blood supply in the damaged area that took the blow, this can cause a quarter crack. If the horse overreache­s and hits the coronary band, it is usually somewhere in the area between the region of the heel nail and the buttress--the back part of the foot.”


When you notice a crack you’d never seen before, you need to make a decision: Do I need to call a farrier right away? Or can this wait until our next scheduled visit? You’ll need to get a close look at it.

In general, the severity of a crack depends upon its depth. Even if they’re long, cracks that are limited to the outer layers of the hoof wall are usually not serious. Most will grow out with the wall and eventually be trimmed off with no harm to the horse. It is, however, a good idea to keep an eye on these blemishes to make sure they do not develop into more significan­t injuries.

The cracks to worry about extend deeper into the hoof wall---enough to weaken it. Call your farrier right away if you discover a hoof crack with any of these signs:

• Instabilit­y of the hoof wall. Watch as a friend walks your horse a few steps on hard, level ground. Does the hoof wall shift as the horse places his weight on it? If you pick up the hoof and handle it gently, you may be able to feel the instabilit­y on each side of the crack.

• Draining fluids. Any blood or pus that appears around the edges of the crack may indicate that the fissure has penetrated all the way to

the interior of the hoof.

• Pain or lameness. Any soreness or unsoundnes­s, however minor, is worth investigat­ing.

• Involvemen­t of the coronary band. Any injury at the coronary band can affect the growth of future hoof wall.

Moshier says he runs into many people who are unsure whether to call the farrier between regular visits to look at a crack. “My answer is that they should call the farrier when the horse is lame as a result of the crack,” he says. If they’re still in doubt, he adds, “I ask my owners to take pictures of the feet with their phone, so they can send a photo to me to ask if it’s something they need to worry about.”


The basic approach to managing any hoof crack, no matter how serious, is to stabilize the hoof and keep the horse comfortabl­e while new horn grows in and the damaged section is trimmed away---this can take up to a year for cracks that started at the top of the hoof. “Trauma to the hoof, such as an abscess, seldom requires more than good regular trimming and in some cases a properly fitted shoe,” says Heather O’Brien, a farrier from

British Columbia.

Bar shoes are often used to help support cracked hooves. “In most cases the farrier will put clips on the shoe---on each side of the crack---to help prevent movement,” says Moshier.

“It depends on the case.”

Not all cracks spread apart when weighted---some toe cracks roll inward and “overlap” when the horse puts weight on the foot. “While people tend to think that we need to stabilize that crack by keeping it together, some types of crack repair involve keeping the edges of the crack apart, so they don’t roll inward,” he adds. “Clips, in this case, won’t do much good.”

More extensive measures may be needed to manage unstable cracks. “Lacing,” for example, involves binding the two sides of the crack together using various materials and techniques, including metal plates or steel wires. “If there is a lot of movement in the crack, we might have to lace it together,” says Moshier. “This can be done by putting horseshoe nails across the crack to hold it together or lacing with stainless steel threads.”

Another option is to use acrylic or polyuretha­ne products to repair cracks and replace lost hoof wall. In more severe cases, the patches may be reinforced with fiberglass. “These stabilize the crack ---essentiall­y gluing it to keep the edges stable so they won’t be moving as the crack grows out,” explains Moshier.

The patch material will then be trimmed away as the hoof wall grows out. “If you apply the patch properly, you can just keep trimming the patch just like the hoof wall as it grows down,” says Boudreau. “If everything works the way it is supposed to, it will grow right on off and then you’ll have a strong, healthy foot again.”

For the most serious cases, when a horse is significan­tly lame and his long-term soundness is at risk, the farrier will need to work in conjunctio­n with a veterinari­an, who can prescribe medication­s to relieve pain and control infections. In some cases, dead or dying tissue may need to be removed, and x-rays may be

needed to look for the position and potential injuries to the coffin bone and other structures within the foot.

Even as the work to stabilize the hoof is under way, it is important to adjust trimming and shoeing to address any hoof imbalances or other stressors that caused the crack in the first place. “The one thing consistent in all successful recoveries from a crack is the proper balancing of the foot to the horse’s conformati­on,” says O’Brien. “Without this, the crack will keep returning until proper balance is restored.”


Simply keeping your horse healthy---with balanced nutrition, not overweight, and plenty of turnout and exercise in good footing---will go a long way toward keeping his hooves strong as well. Beyond that, you can take additional steps to reduce the risk of hoof cracks:

• Stay on schedule with your farrier. Whether the horse is barefoot or shod, regular visits from your farrier are important to keep his feet properly trimmed and balanced in accordance with his conformati­on. Flares that form at the bottom of overgrown hooves can easily form cracks. “When the hoof wall gets too long it will bend, then crack,” says O’Brien. “Debris from the environmen­t can become

embedded in the crack, especially if the horse is barefoot, causing abscesses and even white-line disease.”

• Use traction aids only when needed. Calks, rims, borium and other traction devices may be invaluable if you often ride on slick surfaces, but they can add stresses to the hooves and legs that can lead to cracks. Your farrier can advise you on the most appropriat­e shoes for the type of riding that you do.

• Add a supplement, if

necessary. A horse whose diet is deficient in important vitamins and trace minerals is likely to have weak, shelly hooves as well as dull, coarse hair. Biotin is the primary ingredient in supplement­s intended to improve hoof health; many also contain minerals such as copper and zinc as well as amino acids and omega-3 and -6 fatty acids. If you suspect your horse may benefit from a hoof supplement, consult with your veterinari­an or an equine nutritioni­st to assess his diet and create a healthier overall ration.

• Stop the stomping. Horses harassed by stable flies in the summer will stomp their feet repeatedly--which can lead to hoof cracks if they’re on hard, dry ground. Fly sprays will repel stable flies, and a number of management strategies can help keep insect population­s under control. These flies breed in decaying organic matter, so clean up soiled bedding and manure from turnout areas daily, and treat the manure pile with insecticid­es or larvicides. If flies remain a problem, consider outfitting your horse with fly boots, which cover the legs and prevent the pests from landing on your horse.

• Keep an eye on footing. Galloping over hard ground poses an obvious risk of cracks, but deep, soft footing also places stresses on the hoof that can cause injury to the hoof wall. Out on the trail, slow to a walk when you encounter ground that is either deep and soft or hard and rocky, and drag your arena frequently to keep the footing uniform.

• Avoid the wet/dry cycle. When hooves get wet, they soften and swell; when they’re dry, they stiffen and contract. Horses can adapt to either condition, but alternatin­g between the two on a daily basis can loosen shoes and cause cracks.

“It’s not just the horse that’s constantly standing in mud, or a horse that lives in a dry desert environmen­t,” says Moshier. “The biggest problems occur when horses are always alternatin­g, such as going from a stall bedded in kiln-dried shavings to being turned out in the muck or wet pastures.” If your turnouts are chronicall­y muddy, look for ways to improve drainage. Laying gravel in high-traffic areas may also help.

• Inspect your horse’s hooves daily. Picking out the hooves is an essential part of good horsemansh­ip, but as you do this chore, take some time to inspect the overall health of the hoof: Run your hand over the hoof wall and coronary band to feel for defects. Look for dark spots on the sole, which could indicate bruising. Wiggle the shoe to check for looseness---if you have a farriery tool called clinchers on hand, you can tighten the clinches. If the shoe is on the verge of falling off, your safest option may be to remove it entirely. “I advise people, when cleaning the feet, to pick the white line and clear everything out of it. That’s the area to look at closely,” says Moshier. “Look for any blackness in the white line because that’s a sign of infection.”

When it comes to hoof cracks, the best advice is simple: Get to know your horse’s hooves. Keep an eye on them and consider taking photograph­s occasional­ly: These can help you determine if a crack is new or if a preexistin­g defect is getting worse.

Keeping your horse’s hooves healthy and strong requires attentive care. But if you can prevent serious hoof cracks, you’ll give him a solid foundation for a lifetime.

Ticks are relentless, blood-feeding ectoparasi­tes that infest almost every type of animal, including horses. With a resume like that you’d think we’d all be on high alert, all the time, to ensure ticks are identified and disposed of before they have the opportunit­y to attach to our horses. However, equine tick infestatio­ns can go undetected, even by conscienti­ous owners, due to the horse’s thick hair coat and the tick’s small size. Couple that with a widespread misconcept­ion that ticks only feed in warmer months of the year or in certain habitats, and ticks persist as a particular­ly icky equine parasite.

But ticks are more than gross. They can cause skin irritation, secondary infections at bite wounds and even anemia. Most concerning, ticks can pass along pathogens, such as those that cause equine piroplasmo­sis and Lyme disease. As global climate trends have led to increasing tick population­s and expanded distributi­ons, these tiny arachnids are becoming an increasing­ly significan­t equine health concern. All of which makes it more important than ever to learn which tick species are most likely to bite your horse and the threats they pose when they do.


Although many species of ticks can infest horses, some are more common than others. Geography, landscape and time of year influence which types of ticks your horse is most likely to encounter (see “Geographic Distributi­on,” page 62). Be aware that even less-common species can cause significan­t health problems, so it’s important to still be on alert for them. Here’s a rundown of ticks that most commonly cause problems in horses.

1. Black-legged ticks or deer ticks (Ixodes scapularis and Ixodes pacificus). These small ticks are dark brown to black in color. Unlike many other North American ticks, black-legged ticks search for hosts (a behavior described as “questing” by entomologi­sts) during the cooler months of the year. They tend to be found on woody understory---the lower level of vegetation---protruding from dense leaf litter in forested regions. They also rely on white-tailed deer to maintain their population­s but will readily feed

on other medium or large mammals. Ixodes scapularis is the black-legged tick found in abundance in eastern North America while Ixodes pacificus is encountere­d west of the Rocky Mountains; both species readily infest horses.

2. Lone star ticks (Amblyomma americanum). This aggressive tick is found most often in wooded areas with ample leaf litter that preserves moisture. Adults may track potential horses using shadows or carbon dioxide from exhalation­s. These ticks are reddishbro­wn, and a female will have a white dot on its back while a male will have white markings along the edge of its body. All three stages (larvae, nymphs, and adults) may be found on horses, although identifyin­g the tiny, immature larvae and nymphs requires close, careful examinatio­n. Historical­ly, the distributi­on of this tick was concentrat­ed in the southcentr­al and southeaste­rn United States, but over the last decade, population­s have extended their range to eastern and midwestern regions.

3. Gulf Coast ticks (Amblyomma maculatum). This ornately patterned and rather large tick thrives in open areas, coastal wetlands and grasslands. It feeds on a variety of hosts regardless of life stage and may be seen questing during the heat of the day when other ticks are taking refuge from the hot sun under leaf litter. As the name implies, this tick is found in regions neighborin­g the Gulf Coast, but population­s have expanded and it can now be found as far north as Kansas in the Midwest and up the East Coast as far as Connecticu­t. This tick is a notoriousl­y deep feeder, leading to significan­t skin trauma at the site of attachment. For example, Gulf Coast ticks can induce a condition called “gotch ear” in horses, mules, cattle and goats, where numerous ticks are attached to the inner and outer surface of the ear pinnae, resulting in severe inflammati­on and droopy ears.

4. Wood ticks (Dermacento­r

variabilis and Dermacento­r andersoni). Virtually identical in shape and markings to one another, wood ticks are brown with a white lacy pattern along the back. These ticks prefer grassy areas near forest boundaries and are often seen along edges of trails. Adults feed on medium to large mammals; a recent study found Dermacento­r variabilis to be the second most common tick infesting horses in the summer. Considered together, wood ticks are found in every region of the United States, though Dermacento­r variabilis (American dog tick) is more prevalent in the Northeast, South, Midwest and along the Pacific Coast, while Dermacento­r andersoni is encountere­d solely in the Rocky Mountain states.

5. Winter ticks ( Dermacento­r albipictus). Uniquely, this tick lives on a single host through all life stages (larva, nymph, adult). Larvae quest for a host in large groups in the cooler months of the year, and after feeding molt to the next life stage on the same host. Because they attach in large numbers and stay on the same host for the entire season, heavy infestatio­ns can cause anemia. Winter ticks survive in a variety of environmen­ts, including open and closed canopy forests. They primarily feed on wild ruminants such as moose, elk and deer, but are often found on cattle and horses.

This tick is widely distribute­d across North America. In its southern range, a solid brown variant (no pattern on the back) predominat­es. In other regions, adult winter ticks have a similar white, ornate pattern as the wood ticks.

6. Asian Longhorned ticks (Haemaphysa­lis longicorni­s). Newly introduced to North America, this reddishbro­wn tick has no markings and is found on a variety of hosts, including horses. Longhorned ticks thrive on long grasses in humid, warm conditions but can survive in a variety of climates. Though the distributi­on is currently concentrat­ed in the eastern United States, where it was first recognized in 2017, this tick has been found as far west as Arkansas and the range is expected to continue expanding since this tick is adaptable to many climates and hosts. In addition, longhorned ticks are parthenoge­nic, meaning no males are needed for successful reproducti­on.

7. Spinose ear ticks (Otobius megnini). Only the immature stages (larva and nymph) of this tick feed on animals, including horses. They usually attach deep in the ear canal. Adults are freeliving in the environmen­t and do not feed on blood. Referred to as a soft tick, based on the lack of a hard outer covering, spinose ear ticks are intensely irritating. An infested horse may franticall­y tilt his head or throw himself to the ground in response to the sensation of ticks feeding in the external ear canal. This tick is most common in the hot, dry environmen­t of the southweste­rn United States and Mexico.


You may be aware of Lyme disease and equine granulocyt­ic anaplasmos­is ---both currently considered the most common tick-borne diseases affecting horses in the United States---but several other pathogens spread by these tiny parasites are also cause for concern. Here’s an overview of the tick-borne diseases most seen in horses:

• Lyme disease. One of the most well-known tick-borne diseases, Lyme disease is caused by the Borrelia burgdorfer­i organism, which is transmitte­d by black-legged ticks. In horses, Lyme disease may cause enlarged lymph nodes, inflammati­on of the eye, neurologic abnormalit­ies and occasional­ly stiffness or lameness. Treatment of Lyme disease in horses, which entails the administra­tion of antibiotic­s, is similar to the protocol for dogs; however, the extent of drug dispersal and effectiven­ess in horses is not fully understood. Given the ongoing range expansion of the tick vector and bacterial pathogen system in North America, equine Lyme disease is of increasing concern. Vaccinatio­n is not available for horses and the true extent of disease after an active infection is

unknown, which makes early diagnosis and treatment by a veterinari­an even more important.

• Equine granulocyt­ic anaplasmos­is. Not to be confused with anaplasmos­is in cattle due to Anaplasma marginale, this disease (equine granulocyt­ic anaplasmos­is) is caused by the tick-borne agent Anaplasma phagocytop­hilum, previously known as Ehrlichia equi. Black-legged ticks are the main vector for this pathogen. The disease is characteri­zed by loss of appetite, lethargy, hemorrhage or lameness. In some horses the condition is self-limiting and does not require treatment, while others improve following administra­tion of antibiotic therapy.

• Equine piroplasmo­sis. Although not known to be endemic in the United States, equine piroplasmo­sis (EP) presents a serious concern and regulatory precaution­s are in place to limit its introducti­on and spread. The disease is caused by protozoan Theileria equi and Babesia caballi, which circulate in the bloodstrea­m. Dermacento­r species, including wood ticks, winter ticks, and the infrequent­ly encountere­d tropical horse ticks (Dermacento­r nitens), can transmit these pathogens as they feed. Although less commonly seen in the United States, cayenne ticks (Amblyomma cajennense complex) were linked experiment­ally to a 2009 outbreak of EP caused by Theileria equi. Occasional cases of EP in the United States occur when horses are exposed to the pathogen through shared blood-contaminat­ed equipment.

Mild forms of EP cause weakness and lack of appetite, while more severe signs include fever, anemia, weight loss, jaundiced mucous membranes, swelling of the limbs and abdomen and labored breathing. Clinical signs are usually related to destructio­n of red blood cells and low platelets. Treatment involves quarantine and anti-protozoal medication, which can take months to years to produce negative antibody tests. Even though most horses recover, some EP cases prove fatal. Regional outbreaks can lead veterinary health authoritie­s to limit horse movement, resulting in industry disruption­s. Unfortunat­ely, infected horses are carriers of the pathogen for life. Therefore, when a case is suspected, state and federal veterinari­ans are notified to perform confirmato­ry diagnostic­s and manage the treatment protocol.

• Novel equine tick-borne infections. In addition to the known disease-causing agents transmitte­d by ticks, there are likely novel tickborne agents that have yet to be characteri­zed or thoroughly described. For instance, preliminar­y research has documented the presence of antibodies to the bacteria Ehrlichia spp. in as many as 30 percent of horses in the central United States, and more commonly in those horses heavily infested with ticks. However, the potential health implicatio­ns of these infections, if any, and the specific bacteria responsibl­e have yet to be identified.

Tick paralysis. Although not caused by an infectious agent, ticks feeding on horses can occasional­ly lead to progressiv­e weakness, ataxia and recumbency in afflicted horses. Referred to as “tick paralysis,” the condition usually occurs when ticks---most often wood ticks in North America---are simultaneo­usly feeding and regurgitat­ing salivary secretions that contain neurotoxin­s. These toxins interfere with nerve cell signals and can lead to ascending paralysis, which starts in the legs and moves up toward the body. Luckily, rapid recovery usually occurs after the removal of all feeding ticks.


Ticks are active year-round, which means horses may be infested at any time if the weather and their habitat allows. As seasonal weather patterns shift, timing of tick activity also changes. And even though immature stages of some species may be found feeding on horses, adults are the stage most often collected. Therefore, the tick threat posed to horses is greatest when adults of each species are most active.

Questing activity varies depending on the region, but generally, lone star ticks, Gulf Coast ticks, wood ticks and longhorned ticks are found on horses in spring and summer. Research has demonstrat­ed that, depending on climate and habitat at a given location, lone star ticks reach peak activity in May, Gulf Coast ticks in July and August, wood ticks in May, June, and July, and current data suggest longhorned ticks peak in July.

In contrast, winter ticks and blacklegge­d ticks (deer ticks) are most active during fall, winter and early spring. Winter ticks are most often collected from horses in Oklahoma in November, December, and January. Activity of

black-legged ticks (deer ticks) commonly peaks in October and November, with a second peak in March and April. Spinose ear ticks have been reported from animals year-round but typically are also more active in winter and spring.

Nobody likes thinking about ticks, but they can’t be avoided. Various tick species are active throughout the year, creating a perpetual equine health threat. Products and strategies for combatting tick infestatio­ns are relatively limited, but there are measures you can take to protect your horse. By increasing your awareness of the ticks in your area, as well as their seasonalit­y and likely habitats, you can anticipate issues and work to keep them at bay.

 ?? ?? Because they can weaken the entire hoof, deep vertical cracks (above) and those that originate at the coronary band and grow downward (below) are considered serious.
Because they can weaken the entire hoof, deep vertical cracks (above) and those that originate at the coronary band and grow downward (below) are considered serious.
 ?? ?? Toe cracks appear on the front third of the hoof. Those that originate at the bottom edge of the wall are typically just a cosmetic concern likely to be eliminated at the next trimming.
Toe cracks appear on the front third of the hoof. Those that originate at the bottom edge of the wall are typically just a cosmetic concern likely to be eliminated at the next trimming.
 ?? ??
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 ?? ?? Because they affect a portion of the hoof wall that flexes as the horse bears weight, quarter cracks tend to cause more trouble than toe cracks.
These cracks are more likely to be unstable and cause lameness.
Because they affect a portion of the hoof wall that flexes as the horse bears weight, quarter cracks tend to cause more trouble than toe cracks. These cracks are more likely to be unstable and cause lameness.
 ?? ?? A coronary band injury can temporaril­y disrupt the production of hoof horn, resulting in defects in the hoof wall.
A coronary band injury can temporaril­y disrupt the production of hoof horn, resulting in defects in the hoof wall.
 ?? ?? Any hoof crack that is unstable or causes lameness is cause for a call to the farrier.
Any hoof crack that is unstable or causes lameness is cause for a call to the farrier.
 ?? ?? Tick infestatio­ns on horses often go undetected because of the thick equine hair coat and the parasite’s small size.
Tick infestatio­ns on horses often go undetected because of the thick equine hair coat and the parasite’s small size.
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 ?? ?? Geographic distributi­on of ticks commonly found on horses in the United States.
Geographic distributi­on of ticks commonly found on horses in the United States.
 ?? ?? Immature ticks of some species may feed on horses, but adults are the stage most often collected. Thus, the threat to horses is greatest when adult ticks of each species are most active. Peak seasonal activity of adult ticks commonly infesting horses
Immature ticks of some species may feed on horses, but adults are the stage most often collected. Thus, the threat to horses is greatest when adult ticks of each species are most active. Peak seasonal activity of adult ticks commonly infesting horses
 ?? ?? These images show ticks feeding on horses in various stages of engorgemen­t (A), and wounds associated with previous tick attachment and feeding (B).
These images show ticks feeding on horses in various stages of engorgemen­t (A), and wounds associated with previous tick attachment and feeding (B).
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