Veterinarians and farriers apply a wide variety of horseshoes to treat the plethora of hoof problems that come our horses’ way, not to mention issues farther up the limb. Injuries to the suspensory ligament (a structure crucial to a horse's limb support system) are notoriously difficult to treat, so veterinarians recently tested a modern version of an age-old solution—the so-called fetlock support shoe—to determine its suitability as a suspensory desmopathy treatment. Nat White, DVM, MS, Dipl. ACVS, reviewed the condition and the study results at the 2013 American Association of Equine Practitioners' Convention, held Dec. 7-11 in Nashville, Tenn.
Suspensory desmopathy is a condition that can result in ligament weakening and stretching, and subsequent excessive fetlock dropping or sinking during weight bearing. While it usually affects the hind limbs, suspensory desmopathy can also occur in the front limbs. Treatment success with traditional options—including rest, support bandages, and anti-inflammatory medication—has been limited. Veterinarians have also started using stem cell or protein-rich plasma (PRP) injection directly into affected ligaments in an attempt to improve healing. Additionally, many affected horses' condition can improve with surgical procedures, such as cutting the deep branch of the lateral plantar nerve (located just below the hock) and splitting the injured segment of the ligament to stimulate healing. White noted however, it is rare for lameness due to rear limb desmopathy associated a dropped fetlock to resolve with rest, shockwave, or surgery.
The fetlock support shoe includes a hammock like structure attached to the back of a shoe, which braces the rear of the fetlock to prevent excessive sinking during weight bearing.
Photo: Coutresy Dr. Nat White
Farriers and veterinarians have used the fetlock support shoe to treat tendon injuries and lacerations since the early 1900s. A hammock like structure attached to the back of a shoe braces the rear of the fetlock to prevent excessive fetlock sinking during weight bearing. White described a modified, 21st century version as a bar shoe with a rearward extension and vertical rods fitted with a hammock of elastic tape that forms a fetlock sling. The horse’s limb is bandaged and well-padded before applying the vertical support bars, which are detachable for ease of adjustments and future bandage changes.
White and colleagues recently evaluated the shoe's impact on seven horses with suspensory ligament injuries and excessive extension of their rear fetlock joints. He said:
- All the animals' damaged ligaments improved when wearing the shoe during strict stall rest for up to eight weeks;
- All but one horse also underwent surgery and/or stem cell or PRP injection;
- Healing was evident with lameness resolution and subjective improvement of the fetlock sinking, with tissue healing confirmed by ultrasound; and
- Of the seven horses, the team was able to follow four long-term, and all four had long-term lameness resolution.
White cautioned that it is more difficult to achieve lameness resolution in horses with very straight hind-limb conformation and dropped fetlocks. This abnormal conformation increases suspensory ligament tension, thereby preventing healing. The fetlock support shoe helps decrease the strain on the ligament during healing.
In addition, he said, because a slight fetlock drop generally remains after treatment this support shoe therapy won’t work for horses aimed at strenuous exercise but may help those used for light riding.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.