Difference between revisions of "Respiratory Parasitic Infections - Pathology"

From WikiVet English
Jump to navigation Jump to search
m
 
(35 intermediate revisions by 3 users not shown)
Line 1: Line 1:
{{toplink
+
#REDIRECT[[:Category:Respiratory Parasitic Infections]]
|backcolour = D1EEEE
 
|linkpage =Cardiorespiratory System - Pathology
 
|linktext =Cardiorespiratory System
 
|maplink = Cardiorespiratory System (Content Map) - Pathology
 
|pagetype =Pathology
 
|sublink1=Respiratory System Inflammation - Pathology
 
|subtext1=RESPIRATORY SYSTEM INFLAMMATION
 
}}
 
<br>
 
==In Dogs==
 
 
 
*Useful websites:
 
**[http://www.ivis.org/advances/Parasit_Bowman/ddb_resp/chapter_frm.asp?LA=1 Cat and dog respiratory parasites (part 1)] - Nasal Mucosa and Sinuses, and Respiratory Parenchyma
 
**[http://www.ivis.org/advances/Parasit_Bowman/ddb_resp2/chapter_frm.asp Cat and dog respiratory parasites (part 2)] - Trachea and Bronchi, and Pulmonary Vessels
 
 
 
===[[Metastrongyloidae|'''''Filaroides osleri''''']]===
 
* = ''Oslerus osleri''
 
*Colonise the [[Trachea - inflammatory#Infectious causes of tracheitis|trachea of dogs]]
 
*Larva and adults accumulate in submucosal nodules of up to 1cm diameter at the tracheal bifurcation.
 
*Minimal inflammatory host reaction to the nematodes when they are alive - the size of the nodule is related to the number and size of the nematodes within it.
 
*When the parasites die, an intense foreign body reaction develops
 
*Tracheal nodules can cause coughing, usually in young dogs <18 months old.
 
*Severe infestation can cause significant occlusion of the airway.
 
*Uncommon, but sometimes seen in coughing greyhounds
 
 
 
===[[Crustacea|''Linguatula serrata'']]===
 
*Synonym: tongue worm
 
*In [[Nasal cavity - inflammatory#Infectious causes of rhinitis|nasal passages]] of dogs, sometimes cats
 
*May reach the [[Paranasal sinuses - inflammatory#Infectious causes of sinusitis|sinuses]]
 
*Heavy infections may cause sneezing, coughing, nasal discharge
 
 
 
===[[Metastrongyloidae|''Angiostrongylus vasorum'']]===
 
 
 
*Adult worms live in the [[Lungs - circulatory|pulmonary arteries]] and '''right side of the heart''' dogs and foxes
 
*Cause a proliferative endoarteritis
 
*More severe damage is caused however by eggs lodging in arterioles and capillaries
 
*In severe infection, this can result in [[Lungs - inflammatory#Infectious causes of pneumonia|pneumonia]] and [[Lungs - circulatory#Pulmonary oedema|pulmonary oedema]] as an acute syndrome
 
*Circulatory impedance can result in congestive cardiac failure
 
*Particularly a problem if dogs eats snails
 
*Gross:
 
**Patchy white appearance with haemorrhagic areas within
 
*Microscopically:
 
**Golden pigment within macrophages (haemosiderin)
 
**Inflammation and scarring of alveolar walls -> enlargement of remaining air spaces
 
*Worms secrete anticoagulant -> haemorrhage in other parts of body
 
*May present as neurological cases due to the haemorrhage
 
*May cause [[Lungs - circulatory#Embolism, thrombosis and infarction|pulmonary thromboembolism]]
 
 
 
===[[Filarioidea|''Dirofilaria immitis'']]===
 
 
 
*Establish in '''heart''' and [[Lungs - circulatory|pulmonary arteries]]
 
*Larvae migrate through connective tissue
 
*Immature adults move to caudal distal pulmonary arteries causing diffuse eosinophilic reaction in lung parenchyma, then migrate back to right ventricle
 
*May cause [[Lungs - circulatory#Embolism, thrombosis and infarction|pulmonary thromboembolism]]
 
 
 
===[[Trichinelloidea|''Capillaria aerophila'']]===
 
 
 
*In [[Nasal cavity - inflammatory#Infectious causes of rhinitis|nasal passages]], [[Paranasal sinuses - inflammatory#Infectious causes of sinusitis|sinuses]], [[Trachea - inflammatory#Infectious causes of traacheitis|trachea]] and [[Bronchi and bronchioles - inflammatory#Infectious causes of bronchitis or bronchiolitis|bronchi]] of cats and dogs
 
*Some dogs cough but often no symptoms
 
*Mild catharral inflammation
 
*In heavy infestation may cause obstruction of the lumen of airways and may develop into secondary [[Lungs - inflammatory#Bronchopneumonia|bronchopneumonia]]
 
 
 
===Toxoplasmosis===
 
 
 
*Caused by [[Tissue cyst-forming coccidia|''Toxoplasma gondii'']]
 
*Cats are definitive hosts but other species may become intermediate hosts if they ingest the oocysts
 
*Usually induces antibody response but remains silent clinically
 
*Often show clinical signs when immunosuppressed
 
*Involves many different tissues
 
*Multifocal necrotising [[Lungs - inflammatory#Interstitial pneumonia|interstitial pneumonia]]
 
*Proliferation of type II pneumocytes
 
*Macrophage and neutrophil infiltration
 
 
 
===[[Metastrongyloidae|''Crenosoma vulpis'']]===
 
 
 
*Mainly parasite of foxes but dogs may become infected from snails and slugs
 
*Adults in [[Bronchi and bronchioles - inflammatory#Infectious causes of bronchitis or bronchiolitis|small bronchi and bronchioles]]
 
*Grossly:
 
**Greyish lesions and consolidation in dorsal aspect of caudal lung lobes
 
*Histologically:
 
**Catharral, eosinophilic bronchitis ans bronchiolitis
 
 
 
==In Cats==
 
 
 
*Useful websites:
 
**[http://www.ivis.org/advances/Parasit_Bowman/ddb_resp/chapter_frm.asp?LA=1 Cat and dog respiratory parasites (part 1)] - Nasal Mucosa and Sinuses, and Respiratory Parenchyma
 
**[http://www.ivis.org/advances/Parasit_Bowman/ddb_resp2/chapter_frm.asp Cat and dog respiratory parasites (part 2)] - Trachea and Bronchi, and Pulmonary Vessels
 
 
 
===[[Crustacea|''Linguatula serrata'']]===
 
*As in dogs above
 
 
 
===[[Metastrongyloidae|''Aelurostrongylus abstrussus'']]===
 
 
 
*Live in [[Lungs - inflammatory|lung parenchyma]] and [[Bronchi and bronchioles - inflammatory#Infectious causes of bronchitis or bronchiolitis|small bronchioles]]
 
*Grossly:
 
**Firm yellow nodules scattered throughout parenchyma, more frequently at periphery
 
*Microscopically:
 
**Eggs and larvae in the alveolar spaces cause a foreign body type reaction (surrounded by mononuclear cells and giant cells)
 
**Submucosal gland hypertrophy and smooth muscle hypertrophy in airway and vessel walls
 
*Associated clinical signs are mild although heavy infestations may -> chronic coughing
 
*The airway eosinophilia which may be detected can be confused with a diagnosis of asthma
 
 
 
===[[Filarioidea|''Dirofilaria immitis'']]===
 
*As in dogs above
 
*Not very infective in cats but one dead adult causes acute pulmonary crisis - [[Lungs - circulatory#Embolism, thrombosis and infarction|thromboembolism]]
 
 
 
===[[Trichinelloidea|''Capillaria aerophila'']]===
 
*As in dogs above
 
 
 
==In Horses==
 
 
 
===[[Ascaridoidea|''Parascaris equorum'']]===
 
*Causes transient [[Nasal cavity - inflammatory#Infectious causes of rhinitis|nasal discharge]] when migrating through [[Lungs - inflammatory#Infectious causes of pneumonia|lungs]]
 
**Foals and weanlings
 
 
 
===[[Trichostrongyloidea|''Dictyocaulus arnfieldi'']]===
 
*Found in smaller [[Bronchi and bronchioles - inflammatory#Infectious causes of bronchitis or bronchiolitis|bronchi]]
 
*Cause of chronic cough
 
*Donkeys are a reservoir mostly without any clinical signs
 
*Gross pathology:
 
**Raised areas of over-inflated pulmonary tissue surrounding small bronchus, containing worms and mucopurulent exudate
 
**Hyperplastic bronchial epithelium
 
**Coiled worms in small bronchi
 
**Peribronchial cuffing
 
**In caudal lung lobes
 
*Histologically
 
**Central coiled parasites and associated chronic catharral bronchitis
 
**Goblet cell hyperplasia
 
**Lymphoid cell infiltration
 
*In [[Hindgut Fermenters - Horse - Anatomy & Physiology|horses]], the worms usually fail to achieve sexual maturity
 
 
 
===[[Coccidia|''Besnoitia bennetti'']]===
 
 
 
*Papilloma like lesions in [[Larynx - inflammatory#Infectious causes of laryngitis|larynx]], skin and sclera
 
*Thick walled parasitic cysts, covered by hyperplastic epithelium, may be ulcerated
 
 
 
==In Cattle==
 
 
 
===[[Trichostrongyloidea|''Dictyocaulus viviparus'']]===
 
[[Image:Dictyocaulus viviparus.jpg|right|thumb|100px|<small><center>Dictyocaulus viviparus (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
 
[[Image:Parasitic bronchitis.jpg|right|thumb|100px|<small><center>Parasitic bronchitis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
 
*Found in [[Trachea - inflammatory#Infectious causes of tracheitis|trachea]] and [[Bronchi and bronchioles - inflammatory#Infectious causes of bronchitis or bronchiolitis|large bronchi]]
 
*Causes parasitic bronchitis, synonyms: bovine dictyocauliosis, husk, hoose
 
*Primary infection:
 
**Penetration phase (week 1)
 
***Larvae migrate to lungs, no clinical signs
 
**Prepatent phase (weeks 1-3)
 
***Development and migration of larvae -> [[Bronchi and bronchioles - inflammatory#Bronchiolitis|bronchiolitis]] -> eosinophilic exudate -> air passage blocked -> alveolar collapse (distal to blockage) -> clinical signs (tachypnoea, coughing)
 
**Patent phase (weeks 4-8)
 
***Egg-producing mature worms
 
***[[Bronchi and bronchioles - inflammatory#Bronchitis|Bronchitis]] - due to mature worms
 
***[[Lungs - inflammatory#Verminous pneumonia|Parasitic pneumonia]] - due to aspiration of eggs and larvae -> cellular infiltration of neutrophils, macrophages, giant cells
 
**Postpatent phase (weeks 8-12)
 
***Majority of worms are expelled
 
***In 25% of cases clinical signs may reappear as a result of alveolar epithelialisation
 
***May be together with [[Lungs - ventilation#Emphysema|interstitial emphysema]] and [[Lungs - circulatory#Pulmonary oedema|pulmonary oedema]], or secondary bacterial infection
 
*Reinfection syndrome:
 
**Immune cattle show clinical signs only if exposed to large numbers
 
**Pathogenesis - large numbers of larvae reach bronchioles where they are killed by immune response
 
**Pathology - parasite granulomata (grey-green, 5mm diameter, macrophages, giant cells, eosinophils) and eosinophilic plugs in bronchioles
 
<small>Above from RVC Parasitology study guide (2005-2006)</small>
 
*Preferentially in dorsocaudaland ventrocaudal regions
 
 
 
*Histologically
 
**Bronchial epithelium may show hyperplasia due to the chronic irritation
 
**Cross-sections of the parasites
 
**Exudate contains many eosinophils
 
**Foci of necrosis in the rest of the lung tissue due to aspiration of eggs and larvae fromhese adults
 
**In mild infestations, the adults are normally expelled in two months - self cure
 
*Repeated infestation and secondary bacterial infection are common
 
 
 
*Two other types of lesion in lung tissue due to this worm have been reported:
 
**Nodules (2-4mm in diameter) with greenish centres in the reinfection of an immune animal - the host mounting a successful defence and preventing larval migration
 
**Pulmonary oedema and emphysema - thought to be a hypersensitivity response to a massive invasion of larvae in previously- sensitised animals - the gross and microscopic appearance is similar to that of [[Lungs - inflammatory#Acute bovine pulmonary emphysema and oedema (ABPEE)|fog fever]]
 
 
 
===Hydatid cysts===
 
[[Image:Echinococcus cysts.jpg|right|thumb|100px|<small><center>Echinococcus cysts (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
 
 
 
*The intermediate stage of [[Cestodes|''Echinococcus granulosus'']] can be found in the lungs of many species, most commonly in lungs of cattle and sheep
 
*They range in size up to 5-10 cm diameter and although of little clinical significance, are important as a zoonosis (can be upto football size in man) and because of carcass condemnation
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
===[[Strongyloidea|''Syngamus laryngeus'']]===
 
 
 
*In [[Larynx - inflammatory#Infectious causes of laryngitis|larynx]] of cattle in Asia and South America
 
 
 
==In Sheep==
 
 
 
===Hydatid cysts===
 
 
 
As in cattle (above)
 
 
 
===[[Insecta|''Oestrus ovis'']]===
 
*Larvae in the [[Nasal cavity - inflammatory#Infectious causes of rhinitis|nasal cavity]] of sheep and goats = Nasal bots
 
*Causes reaction in [[Paranasal sinuses - inflammatory#Sinusitis|sinuses]]
 
[[Media:Oestrus ovis.mp4]]
 
 
 
===[[Metastrongyloidae|''Protostrongylus'' spp.]]===
 
*Adult worms block small [[Bronchi and bronchioles - inflammatory#Infectious causes of bronchitis or bronchiolitis|bronchioles]] resulting in accumulation of eggs, larvae and cellular debri distal to the blockage
 
*Lesions resemble [[Respiratory Parasitic Infections - Pathology#Dictyocaulus filaria|''Dictyocaulus filaria'']] but are fewer in numbers, lobular and at periphery of caudal lobes, they are very similar to [[Respiratory Parasitic Infections - Pathology#Muellerius capillaris|''Muellerius capillaris'']] lesions
 
 
 
===[[Metastrongyloidae|''Muellerius capillaris'']]===
 
 
 
*Common in sheep and goats
 
*Rarely any clinical significance
 
*Grossly:
 
**Multifocal [[Lungs - inflammatory#Interstitial pneumonia|interstitial]] [[Lungs - inflammatory#Infectious causes of pneumonia|pneumonia]] grossly evident as firm "lead-shot" nodules throughout the parenchyma, often with enveloping granulomatous response
 
**Early stages are reddish in colour, turning later to greyish green, may calcify
 
**Mostly in dorsal region of caudal lung lobes
 
*Histologically:
 
**Damaged alveolar septa with mild fibrous thickening and lymphocytic infiltrate
 
**In more developed host resistance, foci of eosinophils around larvae, hyperplastic epithelium, macrophages, giant cells
 
**May be some calcification
 
 
 
===[[Trichostrongyloidea|''Dictyocaulus filaria'']]===
 
 
 
*Most susceptible when first exposed to contaminated pasture
 
*Animals < 1 year old
 
*Pathogenesis and pathology similar to [[Respiratory Parasitic Infections - Pathology#Dictyocaulus viviparus|''Dictyocaulus viviparus'']] in cattle
 
*[[Bronchi and bronchioles - inflammatory#Infectious causes of bronchitis or bronchiolitis|Bronchitis]]
 
 
 
==In Pigs==
 
 
 
===[[Metastrongyloidae|''Metastrongylus'' spp.]]===
 
 
 
*Found in [[Bronchi and bronchioles - inflammatory#Infectious causes of bronchitis or bronchiolitis|bronchioles and smaller bronchi]]
 
*Grossly:
 
**Small grey nodules, especially along ventral border of caudal lobes
 
**Adult worms in bronchi and bronchioles
 
*Histologically:
 
**Catarrhal and eosinophilic bronchitis and bronchiolitis
 
**Possibly [[Lungs - ventilation#Atelectasis (Collapse)|atelectasis]]
 
*Rarely becomes extensive
 
*May transmit [[Respiratory Viral Infections - Pathology#Swine influenza|swine influenza]]
 
 
 
===[[Ascaris suum|''Ascaris suum'']]===
 
 
 
*May cause [[Lungs - inflammatory#Verminous pneumonia|parasitic pneumonia]] during a part of its migration
 
*Larvae may be infected with [[Respiratory Viral Infections - Pathology#Swine influenza|Swine influenza]]
 
*May cause severe pneumonia in calves housed where infected pigs were housed previously
 
*Cause diffuse [[Lungs - inflammatory#Interstitial pneumonia|interstitial pneumonia]] with haemorrhage, [[Lungs - ventilation#Atelectasis (Collapse)|atelectasis]], [[Lungs - circulatory#Pulmonary oedema|interlobular oedema]] and [[Lungs - ventilation#Emphysema|emphysema]]
 

Latest revision as of 11:11, 20 July 2010