Mycotic aneurysm in the aortic arch of a horse associated with invasive aspergillosis

AN aneurysm is a localised, abnormal dilation of any vessel. Aneurysms are most important when they affect the aorta in human beings and domestic animals (Robinson and Maxie 1993, Derksen and others 1998). In the horse, various lesions have been described in the aorta, including the formation of a dissecting aortic aneurysm (Holmes and others 1973, Shirai and others 1999), a ruptured aneurysm (Rooney 1979, Roby and others 1986) and a verminous aneurysm (Greatorex 1977), but reports of a mycotic aneurysm in the horse are uncommon. Mycotic aneurysms of the aorta caused by fungi are rare, and are frequently associated with a poor prognosis, as the diagnosis is usually based on an insidious presentation in human beings (Silva and others 2000). This short commu-nication describes a case of a horse with a mycotic aneurysm of the aortic arch caused by