title: Anatomic, radiographic and physiologic comparisons of the internal carotid and maxillary artery in the horse.
abstract: The anatomy of the internal carotid and maxillary arteries was examined using angiography, subtraction angiography and arterial cast preparations in three horses. Subtraction angiography was superior to angiography in demonstrating the anatomy of the occipital, external ophthalmic, ethmoidal and palatine arteries. In three horses manipulation of the internal carotid and occipital arteries during angiography resulted in vasospasm which prevented filling of these vessels with contrast. Direct arterial blood pressure measurements of the maxillary artery impinging on the guttural pouches was measured in four anaesthetized and standing horses. Arterial pressure recordings from the maxillary artery indicate there is retrograde blood flow from contralateral vessels into the occluded arterial segment. Vasospasm prevented measurement of arterial pressure in the internal carotid artery.
authors.affiliation: Young-Crawford Veterinary Clinic, Innisfail, Alberta, Canada.
authors.forename: D G
authors.initials: DG
authors.lastname: Macdonald
authors.forename: P B
authors.initials: PB
authors.lastname: Fretz
authors.forename: K E
authors.initials: KE
authors.lastname: Baptiste
authors.forename: D L
authors.initials: DL
authors.lastname: Hamilton
mesh_terms: D000792:Angiography / Q000662:veterinary; D000818:Animals; D001794:Blood Pressure; D002343:Carotid Artery, Internal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology; D006736:Horses / Q000033:anatomy & histology*; D008438:Maxillary Artery / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology; D012039:Regional Blood Flow