Anatomical Variation of Equine Internal Maxillary Artery: a Case Study

Abstract

A thematic block is taught in the Veterinary Medicine Program at La Salle University’s Faculty of Agricultural Sciences that is relevant to the basic disciplinary training of future veterinarians. It is the theoretical and practical subject of the anatomy of the head of domestic species, which includes the head of horses. The study is addressed by testing the theory in the exercise of a dissection, and the exploration of the different structures that make up the head. This regional and systematic study includes angiology of the head, where emphasis is made on the branches of the common carotid artery as main vessel that irrigates the head. The common carotid artery ends in the occipital, internal carotid and external carotid arteries; the last one splits into two main terminal branches, namely: the internal maxillary artery and the superficial temporal. Generally, the internal maxillary artery follows a path that is repeated in almost all specimens that are dissected as described by different authors; however, in some cases there may variations in the path of the artery, such as in its branches. The purpose of this work is to inform about a case that arose in a regular class in the anatomy lab during dissection of a horse head where arteries were being studied macroscopically. Dissection showed a variation in the normal path of the internal maxillary artery at the level of lateral pterygoid muscle. The case involves an 11-year old mare that was put down by unqualified personnel outside the campus, and whose head was later severed and sent to the gross anatomy labs of the Veterinary Medicine program at the Faculty of Agricultural Sciences. Given its provenance, it was not possible to know the anamnesis, nor the history of the animal.