Auricular pavilion arteriography in cattle

Abstract

Although bovine auricular pavilion has been considered to have large surface vessels, descriptions of its vascularization are scarce. Notwithstanding this region has been used as an alternative route of administration of drugs. With help of an Anatomical specimen, arteriography and dissection have revealed a vast vascular network in the auricle. In this sense, once considered, this knowledge is capable of minimizing prospective complications from the unsuitable use of this region for therapeutic and anesthetic procedures. This study aimed to standardize and describe the arteriography of bovine auricular pavilion in order to acquire a greater knowledge about the local vasculature. Five steers, about one-year-old and weighing about 200 kg, were used, among which three Holstein x Gir crossbred and two Gir purebred. None had lesions in the ear. Of these, two animals were submitted to the standardization of procedures for arteriographies; two others underwent the examination itself. Another bovine, from necroscopy, was subjected to dissection of the ear. The arteriographic images and anatomic dissection pictures were compared to describe anatomical relationships. Arteriography enabled the visualization of lateral, lateral intermediate, intermediate, medial intermediate auricular branches, as well as the medial auricular branch. Conversely, the dissection of the superficial cervicoauricular muscle, between the auricular pavilion and the cornual process base, indicated a poor subcutaneous vascularization of this region, contrasting the rich vascularization near the auricular pavilion. The auricular pavilion arteriography identified a complex vascular network, which in terms of a practical application precludes the administration of slow-absorption drugs in this area. Nevertheless, the dissection images showed the poor subcutaneous vascularization of superficial cervicoauricular muscle surrounding area, making this site more favorable for the administration of long-acting substances.