lymphoid interstitial pneumonia

lymphoid interstitial pneumonia (LIP),

a form of pneumonia involving the lower lobes with extensive alveolar infiltration by mature lymphocytes, plasma cells, and histiocytes. It is associated with human immunodeficiency virus infection, especially in children; dysproteinemia; and Sjögren's syndrome. This is an AIDS-defining illness in children.

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pneumonia

inflammation of the parenchyma of the lung. It is often accompanied by inflammation of the airways and sometimes of the adjoining pleura. Clinically it is manifested by an increase in the rate and depth of respiration at all degrees of severity up to dyspnea. There is also cough, and abnormality of the breath sounds on auscultation. In bacterial pneumonia there is usually a severe toxemia, in viral pneumonia it is usually minor. See also bronchopneumonia, pleuropneumonia.

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Arabian foal pneumonia

an inexorably progressive pneumonia of certain Arabian foals born with primary severe combined immunodeficiency in which adenovirus plays a dominant role but is complicated by other microorganisms, particularly Pneumocystis carinii.

aspiration pneumonia

see aspiration pneumonia.

atypical pneumonia

histologically the pneumonia is atypical in that there are no signs of acute inflammation and it is characterized by an exudation of eosinophilic, protein-rich fluid in the alveoli which may become organized to form a hyaline membrane. In animals that survive for several days there is epithelialization of the alveolar walls. In humans there is a primary atypical pneumonia caused by Mycoplasma pneumoniae. In animals the best known example is atypical interstitial pneumonia of cattle.

bronchointerstitial pneumonia

the lesions are centered on the bronchioles and a prominent feature is the accumulation of lymphocytes in interstitial tissue; typical of pneumonias caused by aerogenous virus infections, especially myxoviruses.

brooder pneumonia

see brooder pneumonia.

chronic undifferentiated pneumonia of sheep

see enzootic pneumonia.

corynebacterial pneumonia of foals

see corynebacterial pneumonia.

cuffing pneumonia

chronic undifferentiated pneumonia of sheep in which lymphofollicular sheaths around the bronchioles are a feature.

equine cryptococcal pneumonia

see epizootic lymphangitis.

desquamative pneumonia

a chronic pneumonia associated with Mycoplasma spp. and characterized by organization of the exudate within bronchioles and bronchi, and proliferation of the interstitial tissue and epithelium.

desquamative interstitial pneumonia

chronic pneumonia with desquamation of large alveolar cells and thickening of the walls of distal air passages; marked by dyspnea and nonproductive cough.

embolic pneumonia

results from hematogenous spread from an intravascular lesion elsewhere in the body. The best known example is caudal vena caval thrombosis.

endogenous-lipid pneumonia

focal alveolar accumulations of foamy, lipid-filled macrophages which may impede alveolar clearance. Usually an incidental postmortem finding in laboratory rodents, fur-bearing animals and uncommonly cats and dogs.

enzootic pneumonia

see enzootic pneumonia.

fibrinous pneumonia

an acute fulminating pneumonia, often lobar in distribution, characterized by a fibrinous exudate. Fibrinous describes the exudate, not the anatomical distribution so that the term fibrinous pneumonia should not be used interchangeably with lobar pneumonia.

foreign body pneumonia

see aspiration pneumonia.

gangrenous pneumonia

usually an accompaniment of aspiration pneumonia.

giant-cell pneumonia

a secondary lesion in dermatosis vegetans in pigs; lesions marked by the presence of a proliferative giant-cell type of diffuse interstitial pneumonia.

granulomatous pneumonia

has a slow course characterized by granulomatous, not exudative, lesions. Sporadic cases occur in immunodeficient animals. It is a characteristic of tuberculosis and systemic fungal infections, e.g. coccidioidomycosis.

hypostatic pneumonia

caused by pooling of blood and some decrease in viability of the dependent lung in an old, sick or debilitated animal that is in lateral recumbency for a long period. The infection is secondary to hypostasis.

inhalation pneumonia

see aspiration pneumonia.

interstitial pneumonia

pneumonia in which there is diffuse or patchy damage to alveolar septa widely distributed through the lungs. There is an early intra-alveolar exudative phase followed by significant proliferation and enlargement of the alveolar epithelial cells and a thickening of the interstitial tissue. Most interstitial pneumonias in animals are infectious including viral, bacterial, fungal and protozoal causes, but may be caused by chemical injury, acute pancreatitis or shock, as in acute respiratory distress syndrome.

lipid pneumonia

a specific type of aspiration pneumonia caused by the inhalation of oil droplets; most commonly associated with the forced administration of paraffin oil or cod-liver oil to cats. Called also medication pneumonia, lipoid pneumonia. See also aspiration pneumonia.

lobar pneumonia

a fulminating bronchopneumonia in which entire pulmonary lobes are diffusively inflamed and then consolidated. Pneumonic pasteurellosis in cattle is the type disease. The animal is critically ill with anoxia and toxemia.

lobular pneumonia

an oldfashioned term for bronchopneumonia.

lymphoid interstitial pneumonia

see maedi.

ovine progressive pneumonia

see maedi.

parasitic pneumonia

see lungworm disease.

stable pneumonia

see equine influenza.

suppurative pneumonia of foals

see corynebacterial pneumonia.

uremic pneumonia

occurs in dogs with terminal uremia; lesions characterized by absence of inflammatory cells.