Megaesôfago secundário a persistência do quarto arco aórtico direito em felino: Relato de caso

Abstract

Persistence of the fourth right aortic arch is characterized by being a congenital vascular ring anomaly most commonly observed in dogs, considered rare in cats, comprising 95% of all vascular ring anomalies found in small animals. This condition results from malformations arising from changes in the embryogenesis of the aortic arches, where the right aortic arch persists in relation to the left aortic arch, leading to esophageal stenosis and, consequently, megaesophagus. The most evident clinical signs are regurgitation, weight loss, excessive appetite, apathy and discomfort after meals, in addition to dehydration and weakness, especially in puppies, in which dry food has recently been introduced. Respiratory signs may be associated with secondary aspiration pneumonia, due to megaesophagus. The diagnosis can be obtained through the analysis of clinical signs together with imaging tests, such as computed tomography, magnetic resonance imaging and simple or contrast radiography of the cervicothoracic region, where esophageal dilatation is visualized mainly with the contrast medium. Treatment is performed through a surgical procedure together with adjustment of dietary management, with a reserved prognosis, according to the clinical picture of each individual. Thus, the present study aims to describe the case report of persistent fourth aortic arch with secondary megaesophagus in a feline, in which the surgical procedure was performed as a treatment method.