Lung lobe torsion (LLT) occurs when a lung lobe rotates along its long axis, causing constriction of the bronchus and vessels at the hilus (Figure 1). This life-threatening disorder requires immediate surgical intervention.

Figure 1. Intraoperative image of a congested, torsed lung lobe. Affected lung tissue is often necrotic and friable. Courtesy of Dr. Karen Tobias, University of Tennessee College of Veterinary Medicine.


LLT occurs spontaneously or secondary to a predisposing condition, such as chylothorax, pleural effusion, or chronic respiratory disease. LLT’s pathophysiology is poorly understood but may involve partial collapse of a lung lobe, either spontaneously or secondary to disease, that leads to altered spatial association and increased relative lung mobility.1 Large, deep-chested dog breeds have a higher incidence of LLT than small-breed dogs; however, pugs may be predisposed.1 Right middle and left cranial lung lobes are most commonly affected.2,3 Median age is 3 years, although LLT has been reported in a 7-week-old pug.3,4

Sign in to continue reading this article

Not registered? Create an account for free to read full articles on

To access full articles on, please sign in below.

Busy? Sign in Faster. Sign into with your social media account.
Up Next