Page 111 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition
P. 111

86                                        CHAPTER 1



  VetBooks.ir  is generally considered as a change in the shape of   the most likely cause of imbalance in shod horses.
                                                          Imbalance also occurs in barefooted horses with
           the hoof that is either indicative of other change that
           is deleterious to function or potentially deleterious
                                                            Imbalance causes lameness by distortion of the
           to function itself. As such, imbalance can be thought   inadequate care or poor conformation.
           of as a disruption of the normal homeostatic mech-  hoof capsule and injury to other structures in the
           anisms that determine the shape of the hoof. Such   limb due to stress redistribution. Dorsopalmar
           disruption could be caused by any event that causes   imbalance is divided into broken back and broken
           the distribution of force on the ground surface of the   forward foot–pastern axis (Fig. 1.147). The former
           foot to change.                                is reported to be associated with navicular disease,
             Both conformation and balance refer at least in   distal DDFT strain, heel bruising, haemorrhage in
           part to the shape of the foot, yet it is convenient to   the dorsal white line and pedal osteitis of the pal-
           divide them into two concepts because of the factors   mar processes. The latter is associated with dorsal
           that influence them. Both are dependent on genetics   sole haemorrhages and pedal osteitis. Mediolateral
           and development, but balance is also affected by hoof   imbalance (Fig. 1.148) is reported to be associated
           growth, wear on the foot, trimming and shoeing,   with sheared heels, quarter or heel cracks, sidebone,
           and the nature of the horse’s work. Conformation is   fracture of the palmar processes and asymmetrical
           largely determined by the time a horse is skeletally   bruising and pedal osteitis, although for the most
           mature, whereas the balance of a foot may continu-  part epidemiological evidence to support these
           ally change throughout the horse’s life. Therefore, in   observations is lacking.
           an adult, attempting to change the limb conforma-  The different changes within the foot that are
           tion by altering the distribution of stresses within the   described as imbalance are often interrelated, but
           hoof is likely to be injurious rather than beneficial.   some of them are frequently discussed as separate
           Poor foot trimming and shoe placement/selection is   entities.



           1.147                                          1.148



























           Fig. 1.147  A broken-forward foot pastern axis with   Fig. 1.148  Hoof imbalance. Mediolateral foot
           lines drawn on the photograph to accentuate the   imbalance with asymmetry of the heel bulbs and
           broken axis.                                   walls of the hoof, sheared and contracted heels, and
                                                          uneven bearing surface of the wall. (Photo courtesy
                                                          Graham Munroe)
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