The July/August 2014 issue of American Farriers Journal included a look at various ways of dealing with hoof cracks, specifically toe cracks.

The article, which appears on pages 30-34, featured three AFJ Editorial Advisory Board members that offered their time-tested ideas for dealing with hoof cracks. Since the issue did not have space for all of their ideas and concerns, we’re providing their ideas here on quarter cracks and bar cracks.

The three farriers included:

Travis Burns, chief of farrier services at the Virginia-Maryland Regional College of Veterinary Medicine in Blacksburg, Va.

Bob Smith, owner of the Pacific Coast Horseshoeing School at Plymouth, Calif.

Steve Stanley a Standardbred track shoer in Versailles, Ky.

Quarter Cracks

Q: What are the primary differences between a quarter crack that starts at the bottom and one that starts at the top?

Burns: A crack starting at the bottom is likely secondary to white line disease (WLD) while a crack beginning at the top of the hoof is likely secondary to mechanical failure.

Smith: A quarter crack that begins on the ground surface is often found with a barefoot horse. A quarter crack that originates at the coronary band is likely due to excessive weight bearing along one side of the hoof.

Stanley: A quarter crack that starts at the bottom is normally a by-product of something else that affected the hoof wall, such as a cavity left by an abscess, hoof wall separation, injury or a broken bar. A crack that starts up higher is due to the stress from uneven loading, such as sheared heels.

Q: If a quarter crack is bleeding, do you have concerns?

Burns: If a crack is bleeding, a vet should be involved and the crack should not be patched at that time.

Smith: Stabilizing a bleeding crack requires more skill. Using polyurethanes or acrylics carry the risk of thermal abscessing. Drain lines must be established, as well as stabilizing the crack. While screws and wires are effective with polyurethanes or acrylics placed over the top, the metal can be hard on your nippers.

A typical quarter crack originating at the coronary band, indicating how the coronet is displaced proximally at the crack.

Stanley: Every time a crack bleeds, it’s getting worse. It drives me crazy to hear a trainer say a hoof has been bleeding a little, but since the horse was sound he went ahead and trained him that day anyway

Q: If you are presented with a base-wide horse with a quarter crack on the inside, what mechanical failures are likely the causes?

Smith: One cause is excessive weight bearing on the medial aspect of the foot. Since balance can be defined as trimming and shoeing the foot so weight is evenly distributed on the foot and up the limb, keep this horse in medial balance shoes.

Stanley: Probably a sheared medial heel.

Burns: The inside of the hoof is overloaded, which reduces hoof wall growth, shunting of the medial heel bulb and encourages the hoof wall to become more vertical. Once this occurs, a loaded hoof does not function normally with a crack or hoof wall failure.

Q: What would be your approach to dealing with the mechanics and the bleeding with the above quarter crack?

Smith: Unless you can shoe for the conformation defect and the horse can successful wear the shoe, stabilizing the crack becomes more difficult.

Stanley: This calls for a bar shoe with lots of breakover and floating of the sheared heel. Debride the crack as much as possible. Have the owner or trainer use a drying agent such as lime every day and reduce the horse’s exercise to prevent further bleeding. After a few days, you can add a patch.

Burns: Radiographs should be used to guide trimming, shoeing and leveling the distal phalanx with the ground. The crack should be debrided to healthy margins, a shoe should be applied to encourage more normal loading of the entire hoof, a rim pad could be incorporated with a portion cut away on the medial side to “float” the sheared heel. Frog and sole support could be used to share the load and to stabilize the distal phalanx within the crack. Wait 3 to 5 days to apply a patch.

Q: Would you recommend changes in the horse’s work or exercise program with this type of crack?

Smith: Tell the manager not to lunge or hot walk the horse as traveling in circles can worsen the condition.

Stanley: Reduced exercise, hand walking, maybe light jogging in the grass and swimming can be helpful in terms of fitness without adding to hoof stress.

Q: Quarter cracks such as this often grow down completely and subsequently fail again, either in the same spot or nearby. Any ideas why?

Burns: Scar tissue is likely making the area weak. Radiographs should be used to guide trimming and shoeing to make sure the horse doesn’t grow out of balance, leading to another crack.

Stanley: Someone fixed the crack, but didn’t address the cause.

Smith: That’s where the excessive forces are concentrated. If the foot was not properly balanced, it can be due to farrier error, the owner’s refusal to pay for special shoes, the environment or the horse being used in a discipline that prevents the use of special shoes, the owner refuses to use bell boots or properly exercise the horse.

Resulting from poor conformation, a sheared heel often occurs in the development of a quarter crack.

Q: After considering the mechanics involved with quarter cracks, what performance requirements and body functions above the foot would you address?

Burns: Increase the horse’s work gradually to allow tissues to respond and strengthen. Reduce the horse’s weight and avoid excessive work and jumping.

Stanley: There’s often a fine line between performance and adequate support. If the crack isn’t fixed, there is no performance.

Q: What care do you expect from the manager of the horse with this crack?

Smith: Take steps to minimize the chance of stepping off the shoe. And no lunging.

Stanley: Keep the hoof clean and dry at all times. Know what is happening each day until the crack is patched, sound and no longer a problem.

Burns: Limit excess stress and strain on the affected area.

Q: How do you approach bilateral quarter cracks on the same foot? Do the mechanics differ from the base wide foot?

Smith: If the bilateral cracks are caused by scar tissue, use bar shoes and proper maintenance. However these cracks can’t be repaired to the point where you again have a normal foot.

Bilateral cracks occur more often in a low heel and long-toed horse. I’d use a heart bar shoe and consider removing hoof material from the crack to the heel so the hoof can grow without pressure.

Stanley: Bilateral quarter cracks often are found with contracted and jammed heels. While it’s hard to float both heels, you need lots of frog pressure. With contracted heels, add as much breakover as possible since these horses are notorious for long toes, thick dorsal walls and delayed breakover.

Bar Cracks

Q: A horse has a bar crack on an otherwise normal hoof and a crack associated with a collapsed heel on the same side. Would you address both cracks in the same manner?

Stanley: No. A bar crack on a collapsed heel is normally caused by an abscessed bruise. The medial heel (often bilateral) on collapsed heels can become badly bruised.

Smith: A bar crack on a normal foot may only need debriding and stabilizing with polyurethanes or acrylics. Since a bar crack associated with a collapsed heel is more complicated and serious, consider using a Z-bar or heart bar shoe after the bar area is resected.

Q: Why are bar cracks often very painful?

Smith: Most pain with cracks comes from “pinching” the sensitive structures as the hoof expands and contracts.

Stanley: It’s often due to heel expansion. Bar cracks also often abscess and lead to infection and extreme pain. They can involve a lot of hoof wall area after an abscess has run its course.

Q: Are there any commercially available products for topical application or mechanical management that you should avoid using?

Stanley: Avoid applying harsh chemicals such as iodine on soft tissue.

Burns: Topical treatments should only be used after careful debridement.

Q: Do you have any thoughts on why these bar cracks seem to be more prevalent than in the past?

Burns: Much of it is due to obesity, poor conformation, breeding horses with poor conformation, not providing a clean dry environment and excessive work or activity.

Smith: Removing too much of the sole, bars and frog, which are designed to support the forces of impact and weight bearing.

Leave the back half of the foot full and unmolested by the hoof knife. Bars should be left level with the wall for at least 3/4 inches. The frog should be left full and trimmed as little as possible, only removing portions that can be grasped with your fingers.

Stanley: Unfortunately, today’s horse breeders do not consider feet when making bloodline decisions. With the advent of new glues, shoes, and other products for hoof care, we can get “breedable” performance from otherwise non-performing horses.