| Line 1: |
Line 1: |
| − | [[Pneumonia Overview]]
| + | #REDIRECT[[:Category:Pneumonia]] |
| − | | |
| − | ==Pneumonia - Introduction and Classification==
| |
| − | [[Image:Acute fibrinous pneumonia.jpg|right|thumb|150px|<small><center>Acute fibrinous pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | *Pneumonia
| |
| − | **Inflammation that takes place in the '''alveoli and their walls'''
| |
| − | **Can be grouped either according to
| |
| − | ***Nature of the inflammatory process
| |
| − | ***Aetiological agent
| |
| − | ***Pattern of the lesion
| |
| − | | |
| − | *Patterns of lung inflammation vary depending on the aetiology, route and method of exposure and multiple host factors including age, general health, and immune status
| |
| − | **There are five general patterns of pneumonia:
| |
| − | ***[[Bronchopneumonia]]
| |
| − | ***[[Bronchointerstitial Pneumonia]]
| |
| − | ***[[Lobar Pneumonia]]
| |
| − | ***[[Interstitial Pneumonia]]
| |
| − | ***[[Embolic Pneumonia]]
| |
| − | | |
| − | | |
| − | [[Category:Pneumonia]]
| |
| − | | |
| − | | |
| − | =='''[[Bronchopneumonia]]'''==
| |
| − | | |
| − | =='''[[Bronchointerstitial Pneumonia]]'''==
| |
| − | | |
| − | | |
| − | | |
| − | =='''[[Lobar Pneumonia]]'''==
| |
| − | | |
| − | | |
| − | =='''[[Interstitial Pneumonia]]'''==
| |
| − | | |
| − | | |
| − | | |
| − | | |
| − | =='''[[Embolic Pneumonia]]'''==
| |
| − | | |
| − | | |
| − | | |
| − | =='''[[Granulomatous Pneumonia]]'''==
| |
| − | | |
| − | | |
| − | | |
| − | | |
| − | =='''Verminous pneumonia'''==
| |
| − | [[Image:Parasitic pneumonia.jpg|right|thumb|150px|<small><center>Parasitic pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | *Lesions in the lung may be due to:
| |
| − | **Parasites passing through the lung as part of their migration e.g. [[Respiratory Parasitic Infections - Pathology#Ascaris suum|''Ascaris suum'']] in the pig, aberrant migration in the case of flukes;
| |
| − | **Parasites for which the lung is the target tissue e.g. [[Respiratory Parasitic Infections - Pathology#Dictyocaulus viviparus|''Dictyocaulus viviparus'']]
| |
| − | *Lesions can vary from interstitial to [[Bronchitis|chronic bronchitis]] to [[Lungs Inflammatory - Pathology#Granulomatous pneumonia|granulomatous pneumonia]]
| |
| − | *May be infiltrate of eosinophils in pulmonary interstitium and bronchoalveolar spaces
| |
| − | *[[Atelectasis|Atelectasis]] and [[Pulmonary Emphysema|emphysema]] may result due to obstruction
| |
| − | | |
| − | | |
| − | | |
| − | [[Category:Pneumonia]]
| |
| − | | |
| − | | |
| − | | |
| − | =Stages of pneumonia=
| |
| − | [[Image:Acute exudative pneumonia.jpg|right|thumb|150px|<small><center>Acute exudative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | [[Image:Acute exudative pneumonia - gross.jpg|right|thumb|150px|<small><center>Acute exudative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | *Regardless of the pattern, all pneumonias pass through three stages:
| |
| − | **'''Exudative phase'''
| |
| − | ***In this initial stage inflammatory exudate pours into alveolar spaces and alveolar capillaries are congested
| |
| − | ***Type I alveolar epithelial cells are highly sensitive to injury and cannot proliferate in response to injury
| |
| − | ***Necrosis and sloughing of injured type I cells, denuding alveolar spaces of lining epithelium
| |
| − | ***[[Neutrophils|Neutrophils]] begin to enter alveolar spaces distended with inflammatory oedema
| |
| − | **'''Proliferative phase'''
| |
| − | ***Type II alveolar cells (less sensitive to and can proliferate in response to injury) begin to proliferate within 24 hours and eventually line the alveolar walls denuded of type I cells ***By 6 days cuboidal type II cells can completely line the alveoli
| |
| − | ***Proliferation of type II cells marks the shift from the exudative to the proliferative stage of pneumonia, also heralded by decreased blood flow in alveolar capillaries
| |
| − | ***Because the original squamous type I cells have been replaced by cuboidal type II cells, the microscopic appearance of pneumonic lungs at about 1 week has been described as “alveolar epithelialization”, “alveolar adenomatosis”, or “bronchiolisation of alveoli”
| |
| − | **'''Repair phase'''
| |
| − | ***Resolution of pneumonia is accomplished by transformation of type II cells to type I cells
| |
| − | | |
| − | | |
| − | | |
| − | =Pulmonary abscesses=
| |
| − | [[Image:Multiple pulmonary abscesses.jpg|right|thumb|150px|<small><center>Multiple pulmonary abscesses (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | *Commonly found post mortem
| |
| − | *Can be a consequence of:
| |
| − | # [[Pulmonary Embolism, Thrombosis and Infarction|'''Septic emboli''']] lodging in the pulmonary vessels
| |
| − | # '''Extension''' from severe focal suppurative [[Lungs Inflammatory - Pathology#Bronchopneumonia|bronchopneumonia]]
| |
| − | # '''Aspiration''' of foreign material (see [[Lungs Inflammatory - Pathology#Aspiration pneumonia|aspiration pneumonia]])
| |
| − | # Direct '''penetration'''
| |
| − | *The pattern of abscessation can suggest the aetiology i.e. multiple widespread abscesses suggest a haematogenous origin; isolated cranioventral abscesses usually arise from suppurative pneumonia.
| |
| − | | |
| − | ='''Infectious causes of pneumonia'''=
| |
| − | {| cellpadding="5" cellspacing="0" border="1"
| |
| − | | .
| |
| − | | [[:Category:Respiratory Viral Infections|'''VIRAL''']]
| |
| − | | [[:Category:Respiratory Bacterial Infections|'''BACTERIAL''']]
| |
| − | | [[:Category:Respiratory Fungal Infections|'''FUNGAL''']]
| |
| − | | [[:Category:Respiratory Parasitic Infections|'''PARASITIC''']]
| |
| − | |-
| |
| − | | '''Dogs'''
| |
| − | | [[Canine Distemper Virus|Canine distemper]]
| |
| − | | usually secondary
| |
| − | | [[Blastomycosis|''Blastomyces dermatitidis'']]
| |
| − | | [[Angiostrongylus vasorum|''Angiostrongylus vasorum'']]
| |
| − | |-
| |
| − | | .
| |
| − | | [[Canine Infectious Tracheobronchitis|Infectious canine tracheitis]]
| |
| − | | bronchopneumonia: ''[[Bordetella bronchiseptica]], [[:Category:Staphylococcus species|Staphylococci]], [[:Category:Streptococcus species|Streptococci]], Coliforms''
| |
| − | | [[Histoplasmosis|''Histoplasma capsulatum'']]
| |
| − | | ''[[Toxoplasma gondii]]''
| |
| − | |-
| |
| − | | .
| |
| − | | [[Canine Herpesvirus 1|Herpes virus]]
| |
| − | | .
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | '''Cats'''
| |
| − | | [[Feline Calicivirus|Feline calicivirus]]
| |
| − | | bronchopneumonia: ''[[:Category:Pasteurella and Mannheimia species|Pasteurella sp.]], [[:Category:Streptococcus species|Streptococcus spp.]]''
| |
| − | | .
| |
| − | | ''[[Aelurostrongylus abstrusus]]''
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Chlamydiosis, Feline|Feline chlamydiosis]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | '''Horses'''
| |
| − | | [[Equine Rhinopneumonitis|Equine rhinopneumonitis]]
| |
| − | | [[Strangles|Strangles]]
| |
| − | | [[Pneumocystis carinii|''Pneumocystis carinii'']]
| |
| − | | ''[[Parascaris equorum]]''
| |
| − | |-
| |
| − | | .
| |
| − | | [[Equine Influenza|Equine influenza]]
| |
| − | | [[Glanders|Glanders]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | [[Equine Viral Arteritis|Equine viral arteritis]]
| |
| − | | [[Rhodococcus equi|''Rhodococcus equi'']]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | '''Cattle'''
| |
| − | | [[Bovine Parainfluenza - 3|Parainfluenza- 3]]
| |
| − | | [[Necrotic Laryngitis]]
| |
| − | | .
| |
| − | | ''[[Dictyocaulus viviparus]]''
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Pneumonic Pasteurellosis|Pneumonic pasteurellosis]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Contagious Bovine Pleuropneumonia|Contagious bovine pleuropneumonia]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Enzootic Pneumonia - Calves|Enzootic pneumonia of calves]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Acute Exudative Pneumonia|Acute exudative pneumonia]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Enzootic Pneumonia - Calves|''Mycoplasmal'' pneumonia]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Tuberculosis - Cattle|''Mycobacterium bovis'' - tuberculosis]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | bronchopneumonia: [[:Category:Pasteurella and Mannheimia species|''Pasteurella sp.'']], ''[[Corynebacterium pyogenes]]''
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | '''Sheep'''
| |
| − | | [[Visna-Maedi Virus|Maedi Visna]]
| |
| − | | bronchopneumonia: ''[[Corynebacterium pyogenes]]''
| |
| − | | .
| |
| − | | [[Muellerius|''Muellerius capillaris'']]
| |
| − | |-
| |
| − | | .
| |
| − | | [[Bovine Parainfluenza - 3|Parainfluenza- 3]]
| |
| − | | [[Enzootic Pneumonia - Lambs|Enzootic pneumonia of lambs]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | [[Sheep Pulmonary Adenomatosis]]
| |
| − | | [[Melioidosis|''Pseudomonas (Malleomyces) pseudomallei'']]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | '''Pigs'''
| |
| − | | [[Porcine Cytomegalovirus|Inclusion body rhinitis]]
| |
| − | | [[Enzootic Pneumonia - Pigs|Enzootic pneumonia of pigs]]
| |
| − | | .
| |
| − | | [[Ascaris suum|''Ascaris suum'']]
| |
| − | |-
| |
| − | | .
| |
| − | | [[Swine Influenza|Swine influenza]]
| |
| − | | [[Actinobacillus pleuropneumoniae|''Actinobacillus pleuropneumoniae'']]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | [[Porcine Reproductive and Respiratory Syndrome|Porcine reproductive and respiratory syndrome]]
| |
| − | | [[Necrotic Laryngitis]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | [[Porcine Circoviruses|Postweaning multisystemic wasting syndrome]]
| |
| − | | [[Pasteurellosis - Pigs|''Pasteurella multocida'']]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | [[Porcine Respiratory Coronavirus|Porcine respiratory coronavirus]]
| |
| − | | [[Contagious Porcine Pleuropneumonia|Contagious porcine pleuropneumonia]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Glasser's Disease|Glasser's disease]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | [[Atrophic Rhinitis|''Bordetella bronchiseptica'']]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | | .
| |
| − | | .
| |
| − | | bronchopneumonia: [[:Category:Pasteurella and Mannheimia species|''Pasteurella'' spp.]], ''[[Corynebacterium pyogenes]]'', also [[:Category:Streptococcus species |''Streptococcus'' spp.]], [[Tuberculosis - Pigs|Tuberculosis]]
| |
| − | | .
| |
| − | | .
| |
| − | |-
| |
| − | |}
| |
| − | | |
| − | | |
| − | | |
| − | ='''Other forms of pneumonia'''=
| |
| − | | |
| − | | |
| − | ===Aspiration pneumonia===
| |
| − | [[Image:Acute necrotising pneumonia.jpg|right|thumb|150px|<small><center>Acute necrotising pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | [[Image:Inhalation pneumonia.jpg|right|thumb|150px|<small><center>Aspiration pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | *Response of the lungs to aspirated foreign material will depend on the nature of the material (e.g. food), the bacterial load and the distribution of the material within the lungs
| |
| − | *Mild bronchopneumonia can develop into a severe necrotising pneumonia and in very severe cases can progress to gangrenous pneumonia (below)
| |
| − | *In Cattle
| |
| − | **Associated with poor husbandry
| |
| − | **Regurgitated ruminal content
| |
| − | **Cranio-ventral distribution
| |
| − | **Respiratory insufficiency secondary to [[:Category:Cardiovascular System - Developmental Pathology|congenital cardiac disease]]
| |
| − | *In Horses
| |
| − | **Most commonly in right ventral lung lobe (most rostral secondary bronchus leads to right accessory lobe)
| |
| − | **Risk factors:
| |
| − | ***[[Oesophagus - Anatomy & Physiology|Oesophageal]] obstruction
| |
| − | ***Spontaneous reflux (GI obstruction, equine grass sickness)
| |
| − | ***[[Respiratory System Clinical Signs - Pathology#Dysphagia|Dysphagia]]
| |
| − | ***Iatrogenic
| |
| − | ****Nasogastric tube in the wrong place
| |
| − | *In Dogs
| |
| − | **Most commonly [[Control of Feeding - Anatomy & Physiology#The Vomit Reflex|vomited]]/regurgitated material or contrast medium introduced into airways
| |
| − | **In severe acute cases may die from septic shock
| |
| − | **In chronic cases -> [[Lungs Inflammatory - Pathology#Bronchopneumonia|bronchopneumonia]]
| |
| − | **Common sequel to [[Myasthenia Gravis|myasthenia gravis]], [[Megaoesophagus|megaoesophagus]] or [[Persistent Right Aortic Arch|persistent right aortic arch]]
| |
| − | | |
| − | [[Category:Pneumonia]]
| |
| − | | |
| − | | |
| − | ===Gangrenous pneumonia===
| |
| − | [[Image:Gangrenous pneumonia.jpg|right|thumb|150px|<small><center>Gangrenous pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | *Can occur following severe infections in which tissue becomes necrotic and is then invaded by putrefactive saprophytes, however this is rare.
| |
| − | *The usual cause is administration of medicines (intended for the oesophagus!) or as a sequel to aspiration pneumonia
| |
| − | *The dead tissue undergoes liquefactive necrosis forming a cavity which is surrounded by intense hyperaemia and inflammation
| |
| − | | |
| − | | |
| − | [[Category:Pneumonia]]
| |
| − | | |
| − | | |
| − | ===Lipid pneumonia===
| |
| − | [[Image:Lipid pneumonia.jpg|right|thumb|150px|<small><center>Lipid pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
| |
| − | *Associated with inhalation of oil, paraffin, etc.
| |
| − | *Reaction dominated by macrophages which fill the alveoli and interstitial thickening (mononuclear cells and fibrosis)
| |
| − | *Tends to acumulate in ventral regions bilterally
| |
| − | *Occurs subclinically in cats, sometimes dogs, unrelated to aspiration
| |
| − | *Gross lesion:
| |
| − | **Multifocal, firm, white nodules
| |
| − | *Microscopic lesions:
| |
| − | **Macrophages full of lipid forming foam within alveoli
| |
| − | **Interstitial lymphocyte and plasma cell infiltration, fibrosis
| |
| − | | |
| − | | |
| − | [[Category:Pneumonia]]
| |
| − | | |
| − | | |
| − | ===Uraemic pneumonia===
| |
| − | *Severe uraemia causes increased permeability of the blood-air barrier and therefore can cause [[Pulmonary Oedema|pulmonary oedema]]
| |
| − | *In addition to the oedema, there may also be degeneration and calcification of smooth muscle and connective tissue fibres
| |
| − | *Lungs do not collapse on opening the thorax in severe cases
| |
| − | | |
| − | | |
| − | [[Category:Pneumonia]]
| |
| − | | |
| − | | |
| − | ===Foetal pneumonia===
| |
| − | *Especially foals and farm species
| |
| − | *Due to aspiration of amniotic fluid contaminated with meconium and bacteria
| |
| − | **Secondary to fetal distress
| |
| − | **Microscopic lesions of [[Lungs Inflammatory - Pathology#Bronchopneumonia|bronchopneumonia]]
| |
| − | **Involves all lobes (versus postnatal bronchopneumonia)
| |
| − | *Haematogenous spread
| |
| − | **Causes [[Lungs Inflammatory - Pathology#Interstitial pneumonia|interstitial pneumonia]]
| |
| − | **Often caused by ''Listeria monocytogenes'', ''Salmonella'' spp. or ''Chlamydia psittaci''
| |
| − | *In viral abortions
| |
| − | **Cause [[Lungs Inflammatory - Pathology#Bronchointerstitial pneumonia|bronchointerstitial pneumonia]]
| |
| − | **E.g.: [[Infectious Bovine Rhinotracheitis|IBR]], [[Bovine Parainfluenza - 3|PI-3]] and [[Equine Rhinopneumonitis|equine viral rhinopneumonitis]]
| |
| − | | |
| − | | |
| − | [[Category:Pneumonia]]
| |
| − | | |
| − | | |
| − | | |
| − | =Test yourself with the Lungs Pathology Flashcards=
| |
| − | | |
| − | [[Lungs_Flashcards_-_Pathology|Lungs Pathology Flashcards]]
| |