The biomechanics of the equine foot as it pertains to farriery.

Shoes were originally applied to horses' feet to protect against excessive wear. Over the years, countless types of shoes and farriery techniques have been developed not only as a therapeutic aid to treat lameness but also to maintain or enhance functionality. The past 3 decades have provided equine veterinarians and farriers with new information relating to limb biomechanics and the effects of various farriery methods. This article describes the principles of foot biomechanics and how they are affected by some of the more common farriery and shoeing techniques.

Digital sheath synovial ganglion cysts in horses.

OBJECTIVES: To report the clinical features of horses with fluid-filled masses associated with the digital flexor tendon sheath (DFTS) and outcome after surgery. STUDY DESIGN: Case series. ANIMALS: Horses (n=10) METHODS: Medical records of horses with fluid-filled masses associated with the DFTS were reviewed and the clinical features, diagnostic methods, treatment, histopathology, and outcome reported. RESULTS: Masses were unilateral (7 hind limb, 3 front limb) and in 8 horses were associated with lameness. In 6 horses, lameness improved by >50% with intrathecal DTFS anesthesia, whereas 2 were less positive but were further improved with perineural anesthesia just proximal to the cyst. Communication between the DFTS and mass was identified in all horses ultrasonographically. Resection of the mass resolved lameness in 7 horses. Histologically (5 specimens), the mass was characterized by a fibrous outer layer without a synovial lining, consistent with a ganglion cyst. CONCLUSION: The histologic appearance of ganglion cysts suggests that they arise from trauma to the sheath wall and may subsequently be a cause of lameness.

In vitro evaluation of a single injection technique for diagnostic analgesia of the proximal suspensory ligament of the equine pelvic limb.

OBJECTIVE: To examine the anatomic relationship of the deep branch of the lateral plantar nerve (DBLPN) with structures of the proximal metatarsal region, and to define the anatomic location of a solution injected using a single injection technique for diagnostic analgesia of the proximal suspensory ligament (PSL). STUDY DESIGN: Descriptive study. ANIMALS: Cadaveric equine pelvic limbs (n=29). METHODS: The proximal metatarsal region of both pelvic limbs (n=5 horses, 10 limbs) was dissected and measurements were made of anatomic structures relative to the head of the 4th metatarsal bone (HMT4). A single injection technique was used to inject dye 15 mm distal to the HMT4, axial to the MT4 at a depth of 25 mm in each limb from 10 equine cadavers (19 limbs). Hindlimbs were dissected and the position of the dye was recorded. RESULTS: DBLPN branched from the lateral plantar nerve (LPN) at a mean distance of 30 mm proximal to the HMT4 and entered the PSL at a mean distance of 17 mm distal to the HMT4. A 2nd DBLPN was observed in 1 of 10 dissected limbs. Blue dye surrounded the DBLPN in 18 limbs (95%). CONCLUSIONS: A single injection technique was likely to have resulted in desensitization of the DBLPN in 18 of 19 limbs (95%). CLINICAL RELEVANCE: This technique provides a reliable method using a single needle puncture for perineural analgesia of the DBLPN for diagnosis of proximal suspensory desmitis of the pelvic limb with a minimal risk of inadvertently desensitizing structures within the tarsal sheath and the tarsometatarsal joint.

An evidence-based assessment of the biomechanical effects of the common shoeing and farriery techniques.

The first aim of this article is to review the progress made in the field of distal limb biomechanics. By understanding limb biomechanics, it is then possible to review the rationale behind a few of the more common techniques that veterinarians routinely use when treating their patients and to evaluate the evidence in support of them.