Brachycephalic obstructive airway syndrome (BOAS): far beyond stenotic nares and elongated soft palate

Abstract

Brachycephalic dogs have gained popularity worldwide in recent years; this preference is associated with the physiognomy of these animals, which resembles childlike features and has an important influence them being chosen as pets. However, selective breeding for extreme brachycephaly, as in the English bulldog, French bulldog and pug breeds, has given rise to a frequently occurring conformational respiratory disorder known as brachycephalic obstructive airway syndrome (BOAS). This is currently one of the most common anatomical disorders in small animals and has received increasing attention for its impact on animal welfare. It is still neglected, as some people consider it normal for brachycephalic breeds to snore, choke and manifest exercise intolerance. Although the most obvious clinical signs are related to breathing, BOAS can cause serious systemic consequences. Continuous respiratory effort in these dogs often results in increased intrathoracic pressure, leading to cardiovascular alterations such as pulmonary hypertension and cardiac overload. In addition, hypoxia can affect multiple organs, contributing to kidney, liver and gastrointestinal dysfunction. Early clinical and surgical management is essential to improve these animal’s quality of life and prevent the progression of respiratory and systemic signs. Raising awareness about the care of brachycephalic dogs is essential, both for owners and veterinarians, in order to minimize the impact of this syndrome. This literature review aims to provide a current overview of BOAS and its systemic repercussions in brachycephalic dogs.