Oertzenweg 19 b
Tel.+49 30 838 62299 Fax.+49 30 838 62529
From the following two phenomena the question arises whether shoeing horses regularly with iron horse shoes and nails may determine a compression of the circumflex artery of the sole and the area it supplies initiated by the direct pressure of the shoeing and thus be the cause for various acute and chronic dysfunctions occurring in hoof shoeing. The first phenomena is the often observed clammy movement of newly shod horses and the second is the detectable extinction of blood vessel patterns in the corium of the hoof when compressed by a hoof examination forceps.
From 31 horses with healthy hooves that died or were euthanized at the Equine hospital of the Free University of Berlin, 71 specimens of hooves were obtained. The specimens were divided in three Groups: 28 of the formerly unshod specimens were shod by different techniques (tightly studded, loosely studded, and normally studded but weakened hoof sole), 18 of the specimens were already shod when obtained and left that way and 25 of the formerly unshod stayed unshod as reference group. The circumflex artery of the sole has been displayed by a radiographic contrast agent study of the coffin bone. Subsequently, the angiograms were examined for disruptions of the contrast filling in the circumflex artery of the sole.
The results of this study did not reveal a correlation between filling defects at the circumflex artery of the sole and shoeing. Twelve percent (3/25) of the unshod reference group, 5,6% (1/18) of the previously shod and 7,1% (2/28) of the experimentally shod specimen showed at least one disruption of the circumflex artery of the sole. Shoeing horses with iron horse shoes and nails using correct shoeing technique could not produce a compression of the circumflex artery of the sole - even in specimens with thin soles.
The experimental assembly did not allow any conclusion as to whether a compression of the circumflex artery of the sole relevant to blood flow could be induced when body weight of the horse and strain of movement are taken into consideration. Furthermore, pathophysiologic mechanism of tissue due to shoeing such as local inflammation triggering contraction of blood vessels and reduction of blood flow could not be observed with this study design. In vivo angiographic studies would be necessary to further evaluate these important questions.