Comparison of results of thoracic radiography, cytologic evaluation of bronchoalveolar lavage fluid, and histologic evaluation of lung specimens in dogs with respiratory tract disease: 16 cases (1996-2000)

Bronchial collapse and bronchial stenting in 9 dogs

BACKGROUND

Principal and lobar bronchial collapse is increasingly recognized as an isolated entity.

OBJECTIVE

Retrospectively describe the procedure and outcomes of dogs undergoing bronchial stenting at a single referral hospital.

ANIMALS

Nine client-owned dogs with variable degrees of collapse of the left principal bronchus (LPB), lobar bronchus 1 (LB1), and lobar bronchus 2 (LB2), and with clinically relevant signs of respiratory dysfunction.

METHODS

Data were collected from patient records. All dogs underwent stenting of the LPB and LB2. Anatomic and functional impairment grades were assigned to each case before and 4 weeks after stenting. Data regarding response to stenting and complications were evaluated.

RESULTS

Bronchial stenting was considered successful in all cases, with all dogs experiencing improved quality of life (QOL), and decreased functional impairment grade at 4 weeks post-stenting. Follow-up of >6 months was available for 6 dogs and of these, 5 were alive at 12 months, 3 were alive at 18 months, and 1 was alive at 24 months. Stent-related complications occurred in 4 dogs, and were resolvable in 3. Two dogs developed pneumothorax, 1 developed recurrent pneumonia, and 1 developed new-onset coughing. All dogs had mild and manageable coughing post-stenting.

CONCLUSIONS AND CLINICAL IMPORTANCE

Stenting of the LBP and LB2 might be an effective option for dogs with advanced collapse of these bronchi and associated signs. Although all included dogs had resolution or improvement of clinical signs considered life-threatening or as affecting QOL, ongoing coughing is expected. Patient selection appears important with regard to achieving successful outcomes.

Imaging and endoscopic diagnosis of lung diseases in small animals. A review

Diagnostic imaging plays a fundamental role in the diagnosis of pulmonary diseases. Radiography, ultrasound, computed tomography, and endoscopy are important tools for achieving a diagnosis. The choice of diagnostic procedure varies according to the patient, the suspected diagnosis and the risk/benefit ratio. Culture, cytology and histology are nearly always necessary to obtain a definitive diagnosis. Several biopsy sampling techniques are described. Surgical biopsies are the gold standard for the diagnosis of bronchiolitis or interstitial lung diseases but often not performed due to the high risk. In humans, the introduction of transbronchial cryobiopsies has led to excellent results in the study of interstitial lung diseases.

Lower airway collapse: Revisiting the definition and clinicopathologic features of canine bronchomalacia

Bronchomalacia (BM) is an inconsistently defined term in dogs, impairing understanding of clinical presentation, therapeutic response and prognosis. Herein the authors propose to clarify the definition of canine bronchomalacia (CBM) as regional to diffuse dynamic airway collapse of segmental and/or subsegmental bronchi with associated clinical signs due to airflow limitation. In contrast to tracheal collapse, mainstem bronchial collapse, and in some cases lobar collapse, CBM requires advanced imaging. Common co-morbid conditions (e.g., chronic bronchitis, mitral valve degenerative disease, etc.) should be identified during a comprehensive diagnostic evaluation. Current empiric treatments advocated in absence of clinical trials documenting efficacy in the dog warrant evaluation, as some (e.g., bronchodilators) may have detrimental effects in certain types of airway collapse in humans. There is no direct treatment for CBM, as defined above, but non-specific therapies and targeted treatment of co-morbid disease may improve clinical signs and quality of life. In this manuscript, the authors provide a review of the different types of airway collapse focusing on CBM, reviewing their definition and etiology, proposing a classification scheme, and discussing clinical signs, diagnostic testing, and treatment. Future studies should focus on both improving understanding of the etiology and natural disease progression of CBM and treatment trials.

THORACIC RADIOGRAPHIC CHARACTERISTICS OF CANINE INFLUENZA VIRUS IN SIX DOGS

Canine influenza virus is an emerging, highly contagious, respiratory pathogen that has not previously been radiographically described. In this retrospective case series study, we describe the thoracic radiographic appearance of confirmed canine influenza virus in six dogs. Radiographic findings varied, but included abnormal unstructured interstitial (one) and unstructured interstitial and alveolar (five) pulmonary patterns, which were distributed cranioventral (four), diffuse (one), and caudodorsal (one). The right middle (five), left cranial (five), and right cranial (four) lung lobes were most commonly affected. Additionally, mild pleural effusion was present in one dog. Intrathoracic lymphadenopathy and cranial mediastinal widening/fluid accumulation were not detected in any dog. Canine influenza virus should be considered as a differential diagnosis for canine patients with respiratory signs and a cranioventral unstructured interstitial to alveolar pulmonary pattern.

Comparison of bronchoalveolar lavage cytospins and smears in dogs and cats

Differences in the cytological interpretation of bronchoalveolar lavage fluid (BALF) after cytospin preparation (CP) or manual smearing of pelleted cells preparation (MSP) were investigated in client-owned dogs and cats with inflammatory or infectious lower respiratory disease. Bronchoalveolar lavage fluid from healthy cats was also examined. With MSP, cell lysis was more frequently observed, and cellular distribution was more heterogeneous throughout the slide. When samples from healthy and diseased animals were considered together, a significantly greater percentage of neutrophils was seen on CP than on MSP slides (P<0.002). Cytospin preparations were considered of better quality in all individual comparisons. Cytospin preparation is advised in the evaluation of BALF with low total cell count. When only MSPs are evaluated, clinicians should be aware that differential neutrophil counts may underestimate the counts found on CP slides.

Effects of age and allergen-induced airway inflammation in cats: radiographic and cytologic correlation

Thoracic radiography is an important diagnostic tool for feline respiratory medicine. The aim of this study was (1) to assess age-related changes of thoracic radiographic views in healthy young cats and (2) to test if experimentally-induced bronchial inflammation by inhaling Ascaris suum (AS) allergens leads to radiographic changes after single or repeated exposures. Healthy cats (n=15-30) aged between 6 and 30 months were evaluated. Eight healthy cats and eight AS-sensitised cats, respectively, inhaled sterile saline or allergen. Radiographs were taken 24h before, and 6, 24 and 48 h after the challenge. Bronchoalveolar lavage (BAL) was performed after the last radiographic examination. AS-sensitised cats underwent three further allergen challenges at 3-month intervals. The radiographic evaluation was based on a scoring system considering bronchial, interstitial and alveolar patterns. A significant age-related increase in interstitial and total radiographic score was detected in healthy cats older than 18 months and in healthy cats older than 24 months. Whilst saline inhalation did not affect radiographic scores, a single AS challenge induced significant changes of all scores within 6-24h. A significant positive correlation between radiographic scores and BAL neutrophils and eosinophils was found. Repeated AS challenges did not induce irreversible changes in radiographic scores.

Diagnóstico citológico de neoplasia pulmonar por meio de lavado broncoalveolar em uma cadela: relato de caso

Relata-se o caso de uma cadela de raça Poodle, de 12 anos de idade, com quadro clínico de tosse crônica não responsiva à terapia medicamentosa. O exame radiográfico mostrou imagem de consolidação do lobo pulmonar esquerdo. O exame de lavado broncoalveolar pelo broncofibroscópio mostrou células epiteliais com características de malignidade, permitindo firmar o diagnóstico de carcinoma pulmonar sem diferenciação entre neoplasia primária ou metastática.

Use of keyhole lung biopsy for diagnosis of interstitial lung diseases in dogs and cats: 13 cases (1998-2001)

OBJECTIVE

To characterize interstitial lung diseases (ILDs) and evaluate use of keyhole lung biopsy for diagnosis of ILDs in dogs and cats.

DESIGN

Retrospective study.

ANIMALS

11 dogs and 2 cats.

PROCEDURE

Medical records of dogs and cats undergoing keyhole lung biopsy to confirm ILDs were reviewed. Signalment, clinical signs, results of thoracic radiography and other respiratory diagnostic tests, postoperative complications, and patient outcome were analyzed.

RESULTS

Clinical respiratory signs included cough, tachypnea, exercise intolerance, and hemoptysis. Thoracic radiographic abnormalities included interstitial, alveolar, and bronchointerstitial patterns and multiple discrete pulmonary nodules. Lung biopsy and histologic examination revealed interstitial pulmonary fibrosis, bronchiolitis obliterans with organizing pneumonia, or unclassified lesions. Outcome after biopsy included no response to treatment, euthanasia, partial or complete remission while receiving medication, and cure.

CONCLUSIONS AND CLINICAL RELEVANCE

Recognition and classification of ILDs in dogs and cats are likely to be important in guiding appropriate treatment and providing accurate prognostic information. Ancillary respiratory diagnostic tests are beneficial in ruling out infectious and neoplastic disorders that may mimic ILDs; however, their present use in the diagnosis of ILDs is limited. Results suggest that keyhole lung biopsy is an effective means for obtaining a specimen for histologic diagnosis in dogs and cats with ILDs.