Computer tomography measurements of the airway and thoracic cavity do not provide support for bronchial conformation as a predisposing factor of left cranial lung lobe torsion in pugs

The objective of this retrospective clinical study was to determine if airway or thoracic cavity measurements in pugs, particularly the left cranial lung lobe, were significantly different from brachycephalic and mesocephalic control. Thoracic computed tomographic studies of 10 pugs, French bulldogs (FB), and Jack Russell Terriers (JRT) were analyzed. Thoracic height: width ratio (H:W), cross-sectional areas of the left mainstem bronchus (CSA LMB), left cranial lung lobe bronchus (CSA LCrBr), left caudal lung lobe bronchus (CSA LCauBr), CSA LCrBr relative to length (CSA LCrBr/length) and CSA LCauBr/length were measured and adjusted to body weight (/kg). CSA LMB/kg, CSA LCauBr/length/kg, and CSA LCrBr/length /kg were smaller in pugs and FB compared with JRT (P < .05), but no differences were found between pugs and FB. Cross-sectional areas of left cranial lung lobe bronchus /kg and CSA LCauBr/kg were smaller in pugs than JRT (P < .05), but no differences were found between pugs and FB or FB and JRT. No difference was found in thoracic H:W between any breeds. This demonstrated that pugs and FB had significantly narrower bronchi CSA/lengths ratios compared with JRT, but this was not limited to the LCBr. Airway measurements were not significantly different between brachycephalic breeds; therefore, the pugs' predisposition to left cranial lung lobe torsion cannot be solely explained by narrower lower airways.

Long-term survival after treatment of idiopathic lung lobe torsion in 80 cases

OBJECTIVE

To report outcomes of dogs treated for lung lobe torsion (LLT) and to determine prognostic factors for survival.

STUDY DESIGN

Retrospective multicenter study from four veterinary teaching hospitals.

ANIMALS

Dogs (n = 80) with LLT.

METHODS

Medical records were reviewed for clinical and histopathological findings. Long-term outcome was assessed with an owner questionnaire. Lung lobe torsion was classified as idiopathic or secondary on the basis of the etiology.

RESULTS

The most represented breeds were pugs (47.5%) and sighthounds (16.2%). The cause of the LLT was considered primary in 77%, secondary in 21%, and unknown in 2% of dogs. Postoperative complications were recorded in 14% of dogs. Overall, 95% of dogs survived to discharge, and median follow-up was 1095 days (range, 7-3809). Owners assessed outcomes and quality of life as excellent in 93% and 89% of dogs, respectively. Primary LLT was associated with a longer survival (median not reached in the study) compared with secondary LLT (921 days; range, 7-2073; P = .001).

CONCLUSION

Overall long-term survival after lung lobectomy for LLT was excellent. Primary LLT was associated with longer survival compared with secondary LLT. Long-term owner evaluation of clinical outcome for dogs undergoing lung lobectomy for LLT was considered excellent.

CLINICAL IMPACT

Dogs with primary LLT undergoing lung lobectomy have a longer survival time compared with dogs with secondary LLT and have an excellent postoperative outcome.

Chronic lung lobe torsion in a pug

This case report documents a chronic presentation of a lung lobe torsion involving the right cranial and right middle lung lobe in a dog and the benefit of CT in aiding in the diagnosis. The patient presented to the referral practice two weeks after clinical signs developed with minimal resting dyspnoea. The referring veterinarian suspected a diaphragmatic hernia and had been medically managing the patient prior to referral. The radiographic findings showed features more consistent with a lobar mass and no pleural effusion was noted. Signs suggestive of lung lobe torsion were seen on the CT scan, except for the absence of pleural effusion. The patient was a pug, a predisposed breed, which further supported the diagnosis. On lateral thoracotomy a lung lobe torsion of the right cranial and right middle lung lobe was found. Unfortunately the patient did not survive the surgery.

Lung lobe torsion in adult and juvenile pugs

Summary

This cases series of 13 pugs with lung lobe torsion (LLT) is the largest case series of pugs in the literature and the first to compare dogs presenting before and after 12 months of age. Similar to previous case series, the median age of pugs with LLT was 17 months; however six dogs were under 12 months of age (3 of 13 were 11–13 weeks at presentation). There were no differences between the dogs that presented younger or older than 12 months old with respect to sex, neuter status, lung lobe affected, duration and nature of clinical signs, time alive after discharge, and complications. The juvenile onset may suggest that some dogs are inherently at risk of LLT. This is intriguing and important as LLT may not be an intuitive diagnosis in a juvenile brachycephalic animal, and practitioners should be aware of this unusual presentation.