IMAGING DIAGNOSIS—SPONTANEOUS PNEUMOMEDIASTINUM SECONDARY TO PRIMARY PULMONARY PATHOLOGY IN A DALMATIAN DOG

A 1.5‐year‐old, 23 kg intact male Dalmatian dog was evaluated for acute respiratory insufficiency without a previous history of trauma or toxic exposition. Imaging revealed pneumomediastinum, pneumothorax, diffuse unstructured interstitial pulmonary pattern, pulmonary interstitial emphysema, and pneumoretroperitoneum. Histopathological evaluation of the lungs revealed perivascular and peribronchial emphysema, mild lymphocytic interstitial pneumonia with atypical proliferation of type II pneumocytes in bronchioles and alveoli. A lung disease resembling fibrosing interstitial pneumonia in man and cats has been previously reported in Dalmatians and should be included as a differential diagnosis for Dalmatians with this combination of clinical and imaging characteristics.     

RADIOGRAPHIC ASPECTS OF Pneumocystis carinii PNEUMONIA IN THE MINIATURE DACHSHUND

The thoracic radiographic changes of Pneumocystis carinii in 7 miniature Dachshunds were reviewed. The dogs were 7–12 months old and presented with polypnea, exercise intolerance and clinical signs suggestive of immune-incompetence. P. carinii pneumonia was diagnosed in all the dogs using transtracheal aspirate cytology and confirmed at postmortem in 3 dogs that died. Radiographically, diffuse pulmonary changes were present and varied from a mild interstitial and bronchial pattern to an alveolar pattern. Radiographic evidence of cor pulmonale was present in 1 dog. The most severe radiographic changes were seen in 2 of the dogs that died.     

Atypical interstitial pneumonia (AIP) in calves and young cattle in Schleswig-Holstein in conjunction with an infection by the bovine respiratory syncytial virus (BRSV)

It is reported on atypical interstitial pneumonia (AIP) in 16 mostly Holstein-Frisian calves and feeders from 13 different farms in Schleswig-Holstein in association with an infection by the respiratory syncytial virus (BRSV). All animals were submitted with identical clinical histories. Macroscopically the lung lesions were characterized by alveolar and interstitial edema and emphysema. Microscopically there was a diffuse interstitial pneumonia with formation of hyaline membranes and multinucleated giant cells. From the investigation material of the 16 animals BRSV was confirmed by direct immunofluorescence with monoclonal antibodies in 4 animals from 4 different farms.     

Radiographic appearance of pulmonary metastases from transitional cell carcinoma of the bladder and urethra of the dog

Eleven cases of histologically proven transitional cell carcinoma of the bladder or urethra of the dog were selected for evaluation and characterization of the varied radiographic appearances of the lungs. In the 8 dogs with metastases, those appearances included radiographically normal pulmonary parenchyma, a semidense, diffuse, lacelike haze referred to as interstitial opacity, nodular interstitial opacity, and consolidations. One affected dog had hilar lymphadenopathy. In the 3 dogs without pulmonary metastases, the radiographic appearance was either normal pulmonary parenchyma or increased unstructured interstitial opacity. Of all dogs in the study, 6 had a radiographic appearance of increased unstructured interstitial opacity. Four of those 6 had histologically proven metastases in the peribronchiolar lymphatics or alveolar capillaries. Dyspnea was not identified in any of the affected dogs. The radiographic appearance for 3 of the 8 dogs with pulmonary metastases was misinterpreted as opacity compatible with age. The radiographic appearance for 1 of the 3 dogs without pulmonary metastases was misinterpreted as highly suspect for metastases.     

Pulmonary intravascular hemangiosarcoma in a cat

A 9-year-old, castrated male Japanese domestic cat presented with a complaint of exertional dyspnea. Based on the radiographic findings, presumptive diagnosis of aspiration pneumonia or primary diffuse pulmonary neoplasia in the right middle lobe was made. Histologically, the pulmonary lesion was characterized by diffuse thickening of alveolar wall with the proliferation of apparently atypical irregular-shaped cells. Immunohistochemical staining using anti-human factor VIII-related antigen antiserum showed positive reaction in the cytoplasm of the atypical cells. According to the findings, the lesion was diagnosed as pulmonary intravascular hemangiosarcoma.     

Ultrastructural features of alveolar lesions in induced respiratory syncytial virus pneumonia of calves

Ultrastructural changes occurred in alveolar epithelium in the acute and repair stages of induced respiratory syncytial virus pneumonia induced in eight calves (calf Nos. 1-7, 3 to 6 days old and calf No. 8, 2 weeks old), using a bovine strain of respiratory syncytial virus. Five of the calves were Friesians, three were Hereford x Friesians, and all were male. Tissues from three mock-infected control calves (two Friesian, one Hereford x Friesian) were also examined. Evidence of respiratory syncytial virus infection was observed in both type I and type II pneumocytes from day 4 to day 8 after infection. Infection of type I pneumocytes frequently resulted in necrosis. The response of type II pneumocytes to respiratory syncytial virus infection varied and included hypertrophy, hyperplasia, and syncytial formation. In some infected type II pneumocytes, there were numerous irregular projections of the cell surface, associated with viral budding. Hypertrophy and hyperplasia of type II pneumocytes, epithelial syncytium formation, and irregular cytoplasmic projections from epithelial cells caused considerable thickening of respiratory membrane and occlusion of alveolar lumina. Neutrophils were frequently observed in close association with virus-infected epithelial cells, but evidence of respiratory syncytial virus infection and replication was not observed in alveolar macrophages or neutrophils. Proliferation of type II pneumocytes appeared to play a major role in maintaining the integrity of the alveolar epithelium during the acute stage of the experimental pneumonia. Increased numbers of type II pneumocytes were present on alveolar walls, particularly from 4 to 8 days after infection, and some alveoli were lined entirely by this cell type. In some areas, however, squamous epithelial cells were also involved in covering exposed alveolar basement membrane.     

A retrospective study of proliferative interstitial lung disease of horses in Florida

Proliferative and fibrosing interstitial lung disease was diagnosed in 20 horses submitted for necropsy between 1982 and 1985. Most of the horses were foals ranging from 3 days to 6 months in age. Six adult horses were affected. The macroscopic and microscopic characteristics of the lesions consisted of proliferative interstitial pneumonia and were similar to those of atypical interstitial pneumonia of ruminants. Based on morphologic features of the lesions, a toxic etiology is suspected for the induction of this naturally acquired primary equine lung disorder, but could not be specifically discovered by historical information.     

Chronic idiopathic pulmonary fibrosis in five dogs

Five dogs presented with chronic and progressive pulmonary illness characterized by progressive dyspnea, exercise intolerance, and significant inspiratory crackles on auscultation. Radiographically, there was a widespread and diffuse interstitial lung pattern with varying degrees of bronchial involvement. Histopathological changes included thickened alveolar septa, interstitial fibrosis, and pneumocyte hyperplasia. Based on the clinical, radiographic, and histopathological changes, a diagnosis of idiopathic pulmonary fibrosis was made. Idiopathic pulmonary fibrosis is a chronic disease characterized by inflammation and fibrosis of the pulmonary interstitium and peripheral airspaces, which has been poorly characterized in the dog.     

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.     

Interstitial lung disease in West Highland White Terriers

Progressive respiratory failure and pulmonary fibrosis in West Highland White Terriers (WHWT) is an apparently genetic disorder of unknown pathogenesis. This study characterizes the light microscopic, ultrastructural, and immunohistochemical features of affected WHWT in comparison with lesions in usual interstitial pneumonia (UIP) of humans. Lesions in WHWT were confined to the expansion of the interstitial space of alveolar septa by extracellular matrix (ECM) determined to be mixtures of type-I and -III collagens. Features of UIP such as intra-alveolar fibroblastic foci, subpleural distribution, and honeycombing were not observed in six WHWT. Comparison with normal dogs showed no apparent increase in septal myofibroblasts. Ultrastructually, the ECM in alveolar septa consisted of large aggregates of periodic collagen filaments underlying alveolar capillaries that were surrounded by thick bands of amorphous to fine fibrillar matrix. This study suggests that chronic pulmonary disease of WHWT is a result of aberrant collagen regulation.     

Immunoperoxidase study of adenovirus pneumonia in dogs

Summary

The pathology of adenovirus pneumonia in 16 dogs is described. Clinically, these dogs had been severely ill, with severe dyspnoea and listlessness, but only faint coughing.

Histopathological lesions could be associated directly with the presence of adenovirus antigens in the lungs of these dogs by using an unlabelled immunoperoxidase technique on paraffin tissue sections. The lesions were focal and located in alveoli and bronchioles. Infected cells were mostly alveolar macrophages and less frequently type I and 2 pneumocytes and bronchiolar epithelial cells. Infiltrating neutrophils and lymphocytes were not observed to be infected.

This type of pneumonia appears to be a fairly well defined clinical and pathological entity in kennel dogs.     

An immunohistochemical study of the pneumonia caused by peste des petits ruminants virus

Ten goats were inoculated with peste des petits ruminants virus, a paramyxovirus closely related to rinderpest virus. All goats developed severe clinical disease, 8/10 having coughing or dyspnea as prominent clinical signs. In addition, all of the goats had stomatitis and diarrhea. Histopathologic and immunohistochemical studies were done only on the respiratory tracts. Pathologic changes ranged from mild multifocal bronchiolitis and bronchitis to severe bronchointerstitial pneumonia. Lesions were more severe in anteroventral than caudal lobes. The histologic nature of the viral process in the goat lungs had many features in common with the processes of pneumonia in dogs, due to canine distemper, or pneumonia in human beings, due to measles virus. Immunohistochemical staining of formalin-fixed, paraffin-embedded respiratory tract tissue was performed using an indirect system with rabbit anti-rinderpest virus serum, biotinylated anti-rabbit antibody, streptavidin-alkaline phosphatase, and nitroblue tetrazolium chromogen. Staining was sensitive, highlighting the presence of viral antigen in both lung and trachea of all goats. Viral antigen was found in both cytoplasm and nucleus of tracheal, bronchial, and bronchiolar epithelial cells, type II pneumocytes, syncytial cells, and alveolar macrophages. In general, the amount of staining correlated directly with the severity of the inflammatory process.     

Radiographic findings in 16 dogs infected with Angiostrongylus vasorum

Thoracic radiographs of 16 dogs infected naturally with Angiostrongylus vasorum showed signs of bronchial thickening, an interstitial pattern and a multifocal and/or peripheral alveolar pattern. In dogs treated with fenbendazole, follow-up radiographs showed that the alveolar pattern had resolved and a mild, hazy interstitial pattern had developed. In contrast with dogs with heartworm (Dirofilaria immitis), no pulmonary vascular lesions were identified.     

Radiographic, computed tomographic, and ultrasonographic findings with migrating intrathoracic grass awns in dogs and cats.

The purpose of this study was to describe the clinical, radiographic, and computed tomographic findings in dogs and cats with migrating intrathoracic grass awns. Thirty-five dogs and five cats with visual confirmation of a grass awn following surgery, endoscopy or necropsy, and histology were assessed. The medical records and all diagnostic imaging studies were reviewed retrospectively. Labrador Retrievers or English Pointers < 5 years of age, with a history of coughing and hyperthermia, were the most common presentations. Seventeen animals had an inflammatory leukogram of which 14 had a left shift or toxic neutrophils. Radiographs were performed in 38 animals and computed tomography (CT) in 14. Thoracic radiographs were characterized by focal pulmonary interstitial to alveolar opacities (n = 26) that occurred most commonly in the caudal (n = 19) or accessory lobes (n = 8). Additional findings included pneumothorax (n = 9), pleural effusion (n = 8), and pleural thickening (n = 7). Pulmonary opacities identified on radiographs correlated to areas of pneumonia and foreign body location. CT findings included focal interstitial to alveolar pulmonary opacities (n = 12) most commonly in the right caudal lung lobe (n = 9), pleural thickening (n = 11), mildly enlarged intrathoracic lymph nodes (n = 10), soft tissue tracking (n = 7) with enhancing margins (n = 4), pneumothorax (n = 6), pleural effusion (n = 4), and foreign body visualization (n = 4). Histologic diagnoses included pulmonary and mediastinal granulomas or abscesses, bronchopneumonia, and pleuritis. Migrating intrathoracic grass awns should be considered as a differential diagnosis in coughing, febrile animals with focal interstitial to alveolar pulmonary opacities, pleural effusion, pleural thickening, and/or pneumothorax on radiographs or CT.     

Acute Atypical Bovine Pneumonia Caused by Ascaris Lumbricoides

A case of acute atypical pneumonia (bovine asthma, pulmonary emphysema, or pulmonary adenomatosis) occurred in a group of cross-bred beef type yearlings in late autumn. Clinical signs included a forced expiratory grunt, excessive salivation, ruminal stasis and, on auscultation over the lungs, pulmonary emphysema and oedema. The cattle had been brought in from a poor summer pasture and housed in a pig pen heavily contaminated with Ascaris lumbricoides eggs as it had contained unwormed feeder pigs all summer.

Fifteen out of seventeen head were affected ten days following housing and all within twenty-four hours. One steer of the group died and at necropsy fourth stage A. lumbricoides larvae were isolated from lungs showing profuse oedema and some emphysema. Histopathological examinations of the lungs showed a diffuse interstitial pneumonia. All remaining animals appeared clinically normal six days following the outbreak.

     

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.     

Clinical signs, clinicopathological findings, etiology, and outcome associated with hemoptysis in dogs: 36 cases (1990-1999)

Hemoptysis, the expectoration of blood or bloody mucus from the respiratory tract at or below the larynx, was retrospectively evaluated in 36 dogs. Cough, tachypnea, and dyspnea were common historical and physical examination signs. Anemia was documented in 11 dogs, but was severe in only one dog. Other clinicopathological findings reflected the underlying diseases. All thoracic radiographs obtained were abnormal; alveolar and interstitial patterns were most common. Diseases predisposing to hemoptysis included bacterial bronchopneumonia (n=7), neoplasia (n=5), trauma (n=5), immune-mediated thrombocytopenia (n=4), heartworm disease (n=4), rodenticide poisoning (n=3), lung-lobe torsion (n=1), left-sided congestive heart failure (n=1), pulmonary hypertension (n=1), and foreign-body pneumonia (n=1). Four additional dogs had more than one underlying disease process. Nine dogs were either euthanized or died in the hospital during the initial visit. While at least half of the 27 dogs discharged went on to completely recover, five dogs discharged were known to have either died or been euthanized as a result of their disease in <6 months.     

A case of interstitial pneumonia associated with Pneumocystis carinii in a foal

Subacute interstitial pneumonia with diffuse alveolar damage, marked macrophage infiltration, and intracellular Pneumocystis carinii cysts is described in a 3-month-old Swiss warmblood foal. Clinically, the disease was characterized by sudden onset of respiratory distress with fatal outcome. Based on serum immunoglobulin G (IgG), IgA, and IgM values, no humoral immunosuppression was detected. Spleen, thymus, and bronchial lymph nodes did not reveal lymphoid depletion, as assessed by immunohistochemical staining of CD-3-positive cells. Immunopathogenesis of pulmonary infections with intracellular agents in foals is discussed.     

The pathology and aetiology of lung lesions in goats infected with caprine arthritis-encephalitis virus

Fifty dairy goats, of various ages, sexes and breeds were selected for examination on the basis of positive serological reactions to caprine arthritis-encephalitis virus (CAEV). Thirty-one had lung lesions including chronic interstitial pneumonia of caudal or cranioventral lobes, bronchopneumonia, verminous pneumonia, pulmonary cryptococcosis or combinations of these. The only infective agent recovered from all the chronic interstitial pneumonia cases examined was CAEV, which was also recovered from lung tissue of 3 goats with arthritis but no lung lesions. The presence of CAEV in lavaged alveolar macrophages from normal lung tissue and from lungs affected with chronic interstitial pneumonia and verminous pneumonia, and the demonstration of a marked increase in nonspecific esterase staining macrophages in areas of chronic interstitial pneumonia, are discussed in relation to the aetiology of the pneumonia.     

RADIOGRAPHIC PATTERNS OF PULMONARY METASTASIS IN 25 CATS

Thoracic radiographs of 25 cats with pulmonary metastatic disease and confirmed primary tumors were reviewed retrospectively. Pulmonary patterns of metastasis were divided into three categories, described as well-defined interstitial nodules, ill-defined interstitial nodules or a diffuse pulmonary pattern. The latter consisted of an alveolar pattern with or without ill-defined pulmonary nodules and/or pleural effusion. More cats presented with pulmonary metastatic disease in the category of either ill-defined nodules (n = 10) or a diffuse pattern (n = 7). Within this group, the most commonly represented primary tumor was mammary gland adenocarcinoma.