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And the Curious Case of Shelby Boykin (Accession 144376). Trisha J Oura, DVM December 20, 2010. Shelby Boykin (144376). 5 mo F Chihuahua Chronic cough x 4 months, increasing in severity and frequency recently History of green nasal discharge, especially when cough is worse
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And the Curious Case of Shelby Boykin (Accession 144376) Trisha J Oura, DVM December 20, 2010
Shelby Boykin (144376) • 5 mo F Chihuahua • Chronic cough x 4 months, increasing in severity and frequency recently • History of green nasal discharge, especially when cough is worse • Multiple courses of antibiotics = improvement/resolution of clinical signs • No known history of trauma • ~25 other dogs at home
Further Diagnostics • Bronchoscopy: • Sacculated appearance to left sided bronchi • Possible blind-ended bronchi • Mucus • Right sided airways are abnormal too • BAL: • Septic, suppurative inflammation • CT:
???? • Could this be congenital bronchial atresia/dysplasia? • Is this all secondary to previous infections?
Bronchiolitis Obliterans • Nonspecific response to lung damage • Epithelial necrosis leads to bronchiole occlusion with fibro-cartilaginous tissue • Can be due to inhaled irritants/toxins, parasites, viral, fungal, bacterial infections • Damage to bronchiolar epithelium formation of polyps of collagen, fibroblasts, inflammatory cells polyps can cause complete obstruction of airway • Causes irreversible airflow obstruction • Reported in dogs, pigs, cattle, rodents, humans (especially after lung and stem cell transplants)—often fatal Almost ∧
Fibrobascular polyps in a bronchiole with necrosis and inflammatory cell infiltration • Atelectasis, discoloration of lung lobes
Post-Infectious BronchiolitisObliterans is Recognized in Pediatrics • Associated with adenovirus, Mycoplasma, flu, syncytial virus, etc • Histopath: granulation tissue plugs within the lumens of small airways and/or complete destruction of airways leaving a scar • Imaging: • Bronchogram: “pruned tree” • HRCT: bronchial dilation, wall thickening, parenchymal and vascular attenuation, areas of collapse, air trapping during expiration • NucMed: patchy decreases in ventilation and perfusion • CXR: variable but can include • unilateral hyperlucency of all/part of a lung which is enlarged • persistent collapse of affected lobe (up to 8 years post in one study)
In the Literature You May Also See BOOP • BronchiolitisObliterans with Organizing Pneumonia • Often reserved for idiopathic version in humans (newer literature uses Cryptogenic Organizing Pneumonia), used somewhat interchangeably in vet med • Case report of 8 yo FS mixed breed with exercise intolerance and dyspneax 1 mo • CXR: diffuse interstitial, BAL: mucus without inflammation, CT: bronchiectasis, patchy consolidation • Diagnosis via histopath • Interestingly, dog had pulmonary hypertension so this could be a rule out for corpulmonale • Treated with steroids
BOOP Continued… • Animal model of BOOP with oleic acid injury • DIFFERENT from ARDS: • ARDS involves diffuse injury to capillary/alveolar endothelium leading to leakage edema • BOOP primarily affects distal airways and adjacent alvoeli and has airway plugging • BUT both could look similar on radiographs
So What? • Shelby remains a mystery • Bronchial atresia/dyplasia seems unlikely given the normal radiographs, unilateral appearance • BOOP (idiopathic entitiy) seems unlikely because Shelby’s disease is not limited to PERIPHERAL airways & her imaging does not fit the few case reports • Post-infectious bronchiolitisobliterans ….. Still an option? • Ultimately needs histopathology • As of 12/19 @ 12pm, Shelby is stable, but in oxygen
References • Bronchiolitisoliterans—dog lung. http://www.vspo.us/vspo/show-page.php?id=565. Accessed 19 Dec 2010. • Castleman, WL. Bronchiolitisobliterans and pneumoia induced in young dogs by experimental adenovirus infection. Am J Pathol. 1985;119:496-504. • Chang AB, JP Masel, B Masters. Post-infectious bronchiolitisobliterans: clinical, radiological and pulmonary function sequelae. PediatrRadiol. 1998;28:23-29. • Li X, et al. Oliec acid-associated bronchiolitisobliterans organizing pneumonia in beagle dogs. Vet Pathol. 2006;43:183-185. • Martin LD, et al. High-resolution CT findings of bronchiolitisobliterans syndrome after hematopoietic stem cell transplantation. J Thorac Imaging. 2008;23:244-250. • Phillips S, et al. Bronchiolitisobliterans with organizing pneumonia in a dog. J Vet Intern Med. 2000;14:204-207.