Downloaded from http://veterinaryrecord.bmj.com/ on December 3, 2014 - Published by group.bmj.com
Paper
Paper Serial CT features of pulmonary leptospirosis in 10 dogs K. Gendron, A. Christe, S. Walter, A. Schweighauser, T. Francey, M. G. Doherr, J. Lang Leptospirosis pulmonary haemorrhage syndrome (LPHS) is a frequent manifestation of Leptospira infection in dogs and is associated with a high morbidity and mortality. Three helical 16-slice thoracic CT scans were performed in 10 dogs naturally infected with Leptospira, within 24 hours of admission, and three and seven days later. Patients were sedated and scanned without breathhold, with a protocol adapted for rapid scanning. One dog died of respiratory failure on the morning following the first scan. On the initial scan, imaging features of LPHS included ground-glass nodules (10/10), peribronchovascular interstitial thickening (10/10), diffuse or patchy ground-glass opacity (9/10), solid nodules (8/10) and consolidation (7/10). Temporary bronchiolar dilation was observed in all dogs in association with peribronchovascular interstitial thickening, which had completely resolved at day 7. Nodules were with few exceptions assigned to the centrilobular region. Regression of lesion severity was observed after each subsequent scan. Consolidation and solid nodules changed over time into lesions of ground-glass attenuation. Pleural effusion (3/10) and mediastinal effusion (2/10) were mild and transient. Lesion severity appeared unassociated with survival to discharge.
Introduction
Leptospirosis, a disease of both humans and animals with a worldwide distribution, is caused by spirochetal bacteria of the genus Leptospira. Although acute renal failure and hepatic failure are the most frequently reported clinical manifestations of the disease in dogs, several reports indicate pulmonary involvement to be commonplace, estimated at 70 per cent in a series of 50 dogs (Kohn 2010). In a prospective study of 27 dogs referred to our institution for treatment of leptospirosis-related disease in 2007, 81 per cent displayed radiological evidence of leptospirosis pulmonary haemorrhage syndrome (LPHS) (Schweighauser and Francey 2008). Of these 27 dogs, 44 per cent died of severe refractory dyspnoea, and necropsy of three dogs confirmed macroscopic and histological evidence of pulmonary haemorrhage. In this study was a control group composed of non-haemodialysed dogs, all of which developed lung involvement, which suggests haemodialysis was not the main cause of bleeding. Reported radiographic findings in dogs with LPHS are mild-to-severe reticulonodular pulmonary opacities Veterinary Record (2013) K. Gendron, Dipl. DMV ECVDI J. Lang, Prof Dr.med.vet. Dipl ECVDI Clinical Radiology Division, VetSuisse Faculty, University of Bern, Bern, Switzerland A. Christe, PD Dr.med. Department of Diagnostic Radiology, University Hospital of Bern, Inselspital, Bern, Switzerland S. Walter, A. Schweighauser, Dr.med.vet. Dipl. ACVIM T. Francey, Dr.med.vet. Dipl. ACVIM Internal Medicine Division,
doi: 10.1136/vr.102046 Vetsuisse Faculty, University of Bern, Bern, Switzerland M. G. Doherr, Prof. Dr. med. vet. PhD Dipl. ECVPH Department of Clinical Research & Veterinary Public Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland E-mail for correspondence: [email protected] Provenance: not commissioned; externally peer reviewed Accepted December 16, 2013
accentuated in the caudodorsal lung fields, focal alveolar infiltrates (Baumann and Flückiger 2001) and caudal interstitial pattern (Kohn 2010). In people, where pulmonary involvement in leptospirosis has been more extensively studied, overt pulmonary manifestations occur in 20–85 per cent of cases (Paganin and others 2007, Gulati and Gulati 2012). Although symptoms are mild in most of these, intra-alveolar haemorrhage as diagnosed on bronchoalveolar lavage (BAL) has been reported to occur in 25.4 per cent of patients with pulmonary involvement and bears no relationship with the severity of leptospirosis (Paganin and others 2009). Pulmonary haemorrhage can also be occult on conventional radiography: thoracic radiographs were read as normal in 38.7 per cent of 31 patients with alveolar haemorrhage confirmed by BAL (Paganin and others 2007). In people, leptospirosis is characterised on thoracic radiographs by small nodular opacities (1–7 mm diameter), with or without areas of consolidation, with a predominantly peripheral distribution (Im and others 1989). Highresolution CT (HRCT), if not necessary for the diagnosis and management of leptospirosis in humans, has proven superior to radiography in demonstrating the extent of the changes. HRCT findings in people include bilateral extensive ground-glass opacities involving all lobes, patchy areas of airspace consolidation, airspace nodules, rarely small pleural effusions and one case of crazy-paving pattern (Marchiori and others 2011). Our goal was to describe pulmonary CT findings in dogs with natural leptospirosis infection, as well as these findings’ changes in magnitude and appearance over time, based on three serial thoracic CT scans. We additionally aimed to determine whether lesion severity correlated with survival.
Materials and methods
Ten dogs referred to the Animal Hospital of the Vetsuisse Faculty, University of Bern, for treatment of acute renal failure were prospectively recruited from June to September 2012. Written owner consent was obtained for this study, which was approved by the Cantonal February 15, 2014 | Veterinary Record
Downloaded from http://veterinaryrecord.bmj.com/ on December 3, 2014 - Published by group.bmj.com
Paper Committee for Animal Experiments (Canton of Bern; permit BE65/12). Leptospirosis was defined as single microagglutination test (MAT) serology ≥1:800 for any of the non-vaccinal serovars, seroconversion, defined as a fourfold increase in MAT titres on double serology, or positive IGM Elisa. Patients weighing less than 10 kg were excluded because of a parallel study’s requirements. Blood testing (chemistry panel, complete blood cell count, coagulation profile), urinalysis, abdominal ultrasound and thoracic radiographs were carried out on the day of admission. Stage of acute renal injury, liver involvement and bleeding diathesis are summarised in Table 1. Grading of renal injury was based on an established clinical staging system (Cowgill and Langston 2011). Liver involvement was defined as bilirubin levels greater than or equal to 10 µmol/l. Disseminated intravascular coagulation was considered present when dogs were thrombocytopenic (thrombocytes
Paper
Paper Serial CT features of pulmonary leptospirosis in 10 dogs K. Gendron, A. Christe, S. Walter, A. Schweighauser, T. Francey, M. G. Doherr, J. Lang Leptospirosis pulmonary haemorrhage syndrome (LPHS) is a frequent manifestation of Leptospira infection in dogs and is associated with a high morbidity and mortality. Three helical 16-slice thoracic CT scans were performed in 10 dogs naturally infected with Leptospira, within 24 hours of admission, and three and seven days later. Patients were sedated and scanned without breathhold, with a protocol adapted for rapid scanning. One dog died of respiratory failure on the morning following the first scan. On the initial scan, imaging features of LPHS included ground-glass nodules (10/10), peribronchovascular interstitial thickening (10/10), diffuse or patchy ground-glass opacity (9/10), solid nodules (8/10) and consolidation (7/10). Temporary bronchiolar dilation was observed in all dogs in association with peribronchovascular interstitial thickening, which had completely resolved at day 7. Nodules were with few exceptions assigned to the centrilobular region. Regression of lesion severity was observed after each subsequent scan. Consolidation and solid nodules changed over time into lesions of ground-glass attenuation. Pleural effusion (3/10) and mediastinal effusion (2/10) were mild and transient. Lesion severity appeared unassociated with survival to discharge.
Introduction
Leptospirosis, a disease of both humans and animals with a worldwide distribution, is caused by spirochetal bacteria of the genus Leptospira. Although acute renal failure and hepatic failure are the most frequently reported clinical manifestations of the disease in dogs, several reports indicate pulmonary involvement to be commonplace, estimated at 70 per cent in a series of 50 dogs (Kohn 2010). In a prospective study of 27 dogs referred to our institution for treatment of leptospirosis-related disease in 2007, 81 per cent displayed radiological evidence of leptospirosis pulmonary haemorrhage syndrome (LPHS) (Schweighauser and Francey 2008). Of these 27 dogs, 44 per cent died of severe refractory dyspnoea, and necropsy of three dogs confirmed macroscopic and histological evidence of pulmonary haemorrhage. In this study was a control group composed of non-haemodialysed dogs, all of which developed lung involvement, which suggests haemodialysis was not the main cause of bleeding. Reported radiographic findings in dogs with LPHS are mild-to-severe reticulonodular pulmonary opacities Veterinary Record (2013) K. Gendron, Dipl. DMV ECVDI J. Lang, Prof Dr.med.vet. Dipl ECVDI Clinical Radiology Division, VetSuisse Faculty, University of Bern, Bern, Switzerland A. Christe, PD Dr.med. Department of Diagnostic Radiology, University Hospital of Bern, Inselspital, Bern, Switzerland S. Walter, A. Schweighauser, Dr.med.vet. Dipl. ACVIM T. Francey, Dr.med.vet. Dipl. ACVIM Internal Medicine Division,
doi: 10.1136/vr.102046 Vetsuisse Faculty, University of Bern, Bern, Switzerland M. G. Doherr, Prof. Dr. med. vet. PhD Dipl. ECVPH Department of Clinical Research & Veterinary Public Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland E-mail for correspondence: [email protected] Provenance: not commissioned; externally peer reviewed Accepted December 16, 2013
accentuated in the caudodorsal lung fields, focal alveolar infiltrates (Baumann and Flückiger 2001) and caudal interstitial pattern (Kohn 2010). In people, where pulmonary involvement in leptospirosis has been more extensively studied, overt pulmonary manifestations occur in 20–85 per cent of cases (Paganin and others 2007, Gulati and Gulati 2012). Although symptoms are mild in most of these, intra-alveolar haemorrhage as diagnosed on bronchoalveolar lavage (BAL) has been reported to occur in 25.4 per cent of patients with pulmonary involvement and bears no relationship with the severity of leptospirosis (Paganin and others 2009). Pulmonary haemorrhage can also be occult on conventional radiography: thoracic radiographs were read as normal in 38.7 per cent of 31 patients with alveolar haemorrhage confirmed by BAL (Paganin and others 2007). In people, leptospirosis is characterised on thoracic radiographs by small nodular opacities (1–7 mm diameter), with or without areas of consolidation, with a predominantly peripheral distribution (Im and others 1989). Highresolution CT (HRCT), if not necessary for the diagnosis and management of leptospirosis in humans, has proven superior to radiography in demonstrating the extent of the changes. HRCT findings in people include bilateral extensive ground-glass opacities involving all lobes, patchy areas of airspace consolidation, airspace nodules, rarely small pleural effusions and one case of crazy-paving pattern (Marchiori and others 2011). Our goal was to describe pulmonary CT findings in dogs with natural leptospirosis infection, as well as these findings’ changes in magnitude and appearance over time, based on three serial thoracic CT scans. We additionally aimed to determine whether lesion severity correlated with survival.
Materials and methods
Ten dogs referred to the Animal Hospital of the Vetsuisse Faculty, University of Bern, for treatment of acute renal failure were prospectively recruited from June to September 2012. Written owner consent was obtained for this study, which was approved by the Cantonal February 15, 2014 | Veterinary Record
Downloaded from http://veterinaryrecord.bmj.com/ on December 3, 2014 - Published by group.bmj.com
Paper Committee for Animal Experiments (Canton of Bern; permit BE65/12). Leptospirosis was defined as single microagglutination test (MAT) serology ≥1:800 for any of the non-vaccinal serovars, seroconversion, defined as a fourfold increase in MAT titres on double serology, or positive IGM Elisa. Patients weighing less than 10 kg were excluded because of a parallel study’s requirements. Blood testing (chemistry panel, complete blood cell count, coagulation profile), urinalysis, abdominal ultrasound and thoracic radiographs were carried out on the day of admission. Stage of acute renal injury, liver involvement and bleeding diathesis are summarised in Table 1. Grading of renal injury was based on an established clinical staging system (Cowgill and Langston 2011). Liver involvement was defined as bilirubin levels greater than or equal to 10 µmol/l. Disseminated intravascular coagulation was considered present when dogs were thrombocytopenic (thrombocytes
