Spinal cord arteries in Canis familiaris and their variations: Implications in experimental procedures

To study the normal disposition and variations of the arteries that supply the spinal cord of Canis familiaris, a colored solution was injected in the aorta of ten adult mongrel dogs. The dissection of these specimens and the analysis of 2 mm thick diaphanous transversal sections of their spinal cords allowed confirming most of the early reports regarding spinal cord arteries in this species. However, great variability was found in the origin of the ventral spinal artery, in the density of the arteries that form the spinal arterial ring, in the spinal arteries originating from segmental arteries and in the presence of the great ventral medullar artery or Adamkiewicz artery, which was found in only half of the specimens. Comparing the results obtained with those commonly described in humans, it is clear that Canis familiaris shows a great similarity in most respects, particularly in those of clinical relevance, namely the greater density of arteries supplying the spinal cord in the cervical and lumbar segments, and the marked variability of the spinal arteries arising from segmental arteries, which end up by playing a major role in the supply of blood caudally to the lower end of the cervical spinal cord. Nevertheless, dogs differ substantially from humans in the origin of the ventral spinal artery and in the origin and presence of the Adamkiewicz artery. Overall, the data show that, from an anatomical standpoint, the dog seems to be a good model for spinal cord ischemia in humans.