[Almost] [Almost] Everything you Everything you wanted to know about lung wanted to know about lung worms…but were afraid to worms…but were afraid to

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Trisha Oura, DVMTrisha Oura, DVM

10/19/0910/19/09

Molly Troxel Molly Troxel Acc#122947Acc#122947

Quick reviewQuick review

The host with most….The host with most…. Definitive: parasite reaches maturity, reproducesDefinitive: parasite reaches maturity, reproduces Intermediate: transitional for developmentIntermediate: transitional for development Paratenic: “reservoir” not needed for developmentParatenic: “reservoir” not needed for development Incidental: “dead-end”, no maturationIncidental: “dead-end”, no maturation

NematodeNematode RoundwormsRoundworms Usually sexual reproductionUsually sexual reproduction Direct/indirect life cyclesDirect/indirect life cycles Examples: hooks, whips, heartwormExamples: hooks, whips, heartworm

TrematodeTrematode FlukesFlukes Almost all parasiticAlmost all parasitic Usually sexual reproductionUsually sexual reproduction Examples: liver and blood flukesExamples: liver and blood flukes

Canine lung wormsCanine lung wormsParasiteParasite Definitive Definitive

HostHostIntermediate Intermediate HostHost

TransmissionTransmission LocationLocation Pathophysiology, clinical signs, Pathophysiology, clinical signs, characteristic lesionscharacteristic lesions

Oslerus osleri Oslerus osleri (Filaroides (Filaroides osleri)osleri)

Wild/domestic Wild/domestic canidscanids

NoneNone Infectious L1 Infectious L1 shed in fecesshed in feces

Submucosal nodules Submucosal nodules in trachea, carina, in trachea, carina, bronchibronchi

Live worms = minimal reactionLive worms = minimal reactionDead worms = foreign body/allergic Dead worms = foreign body/allergic reactionreactionDx: BaermannDx: Baermann

Eucoleus Eucoleus aerophilius aerophilius (Capillaria (Capillaria aerophilia)aerophilia)

Wild/domestic Wild/domestic canidscanids(occasional (occasional cats)cats)

EarthwormEarthworm Ingestion of Ingestion of intermediate; intermediate; eggs shed in eggs shed in fecesfeces

AirwaysAirways Mild = asymptomaticMild = asymptomaticSevere = chronic cough/dypneaSevere = chronic cough/dypneaSecondary pneumoniaSecondary pneumoniaDx: BaermannDx: Baermann

Crenosoma Crenosoma vulpisvulpis

Fox, occasional Fox, occasional domestic dogsdomestic dogs

Snails, slugsSnails, slugs Larvae shed in Larvae shed in feces, ingestion of feces, ingestion of intermediatesintermediates

Small bronchi and Small bronchi and bronchiolesbronchioles

Eosinophilic bronchitis, bronchiolitis; Eosinophilic bronchitis, bronchiolitis; alveolar granulomatous lesionsalveolar granulomatous lesions

Filaroides hirthiFilaroides hirthi Research beagle Research beagle coloniescolonies

NoneNone Infectious larvae Infectious larvae shed in fecesshed in feces

Alveoli, small bronchiolesAlveoli, small bronchioles Granulomatous pneumonia, can be fatal Granulomatous pneumonia, can be fatal in immunocompromisedin immunocompromisedDdx: Ddx: Andersonstrongylus milksiAndersonstrongylus milksi

Linguatula Linguatula serrata**serrata**

Carnivores, Carnivores, repitles, repitles, amphibiansamphibians

HerbivoresHerbivores Ingestion of Ingestion of intermediatesintermediates

Nasal passages, Nasal passages, sinuses; rarely sinuses; rarely pulmonary pulmonary parenchyma/abdominal parenchyma/abdominal orgaansorgaans

Encysted nymphs can be in LN, Encysted nymphs can be in LN, abdominal organs, pulmonary abdominal organs, pulmonary parenchyma; otherwise = small nodulesparenchyma; otherwise = small nodules

Feline lung wormsFeline lung wormsParasiteParasite Definitive Definitive

HostHostIntermediate Intermediate HostHost

TransmissionTransmission LocationLocation Pathophysiology, clinical signs, Pathophysiology, clinical signs, characteristic lesionscharacteristic lesions

Aelurostrongylus Aelurostrongylus abstrususabstrusus

CatsCats Snails, slugsSnails, slugsParatenics: Paratenics: birds, rodents, birds, rodents, frogs, lizardsfrogs, lizards

Intermediate Intermediate ingestion; ingestion; larvae migrate larvae migrate to lungsto lungs

Adults in Adults in terminal/respiratory terminal/respiratory bronchioles; eggs = bronchioles; eggs = nodules in alveolinodules in alveoli

May be asymptomatic; heavy May be asymptomatic; heavy infestation = chronic cough, incr RRinfestation = chronic cough, incr RREosinophilic reactions to migrating Eosinophilic reactions to migrating larvae; nodules to coalescing larvae; nodules to coalescing consolidation; occasional consolidation; occasional mineralization; chronic eosinophilic mineralization; chronic eosinophilic bronchitisbronchitis

Paragonimus Paragonimus kellicottikellicotti

Mink, fish-Mink, fish-eating eating carnivores; carnivores; domestic domestic catscats

SnailsSnails crabs/crayfishcrabs/crayfish

Metacercariae Metacercariae released from released from intermediates intermediates into GI; migrate into GI; migrate to lungsto lungs

Interstitium, bronchiInterstitium, bronchi Nodules (can be cavitated) and Nodules (can be cavitated) and cysts (matured); eosinophilic cysts (matured); eosinophilic bronchitis/pleuritis; rarely bronchitis/pleuritis; rarely pneumothorax from ruptured cystspneumothorax from ruptured cysts

Heartworms Heartworms ParasiteParasite Definitive Definitive

HostHostIntermediate Intermediate HostHost

TransmissionTransmission LocationLocation Pathophysiology, clinical signs, Pathophysiology, clinical signs, characteristic lesionscharacteristic lesions

Dirofilaria immitisDirofilaria immitis DogsDogsCats, wild Cats, wild canids/felids, canids/felids, sea lions, sea lions, ferret, ferret, humanshumans

Mosquito Mosquito ((Culex, Culex, Aedes, Aedes, AnophelesAnopheles))

Infectious Infectious larvae (3 larval larvae (3 larval stage in stage in mosquitoes)mosquitoes)Up to 6-8 Up to 6-8 month month prepatent prepatent periodperiod

Pulmonary arteries, Pulmonary arteries, right heart; aberrant right heart; aberrant migrationsmigrations

Cardiac dysfunction, pulmonary Cardiac dysfunction, pulmonary hypertension, thromboemboli, hypertension, thromboemboli, pulmonary granulomas, eosinophilic pulmonary granulomas, eosinophilic pneumonitis, caval syndromepneumonitis, caval syndrome

Angiostorngylous Angiostorngylous vasorumvasorum

Dogs, foxesDogs, foxes Snails, slugsSnails, slugs Ingestion of Ingestion of intermediatesintermediates

Pulmonary arteries, Pulmonary arteries, right heartright heart

Chronic heart failure, acute Chronic heart failure, acute interstitial/granulomatous interstitial/granulomatous pneumonia, DIC, aberrant migration pneumonia, DIC, aberrant migration (uveitis), thromboemboli (kidneys, (uveitis), thromboemboli (kidneys, brain)brain)

Radiographic findingsRadiographic findings

Diffuse bronchial pattern (thickened Diffuse bronchial pattern (thickened airway walls with chronic inflammation)airway walls with chronic inflammation) ddx: PIE, chronic bronchitis, ddx: PIE, chronic bronchitis,

bronchopneumonia, allergic diseasebronchopneumonia, allergic disease Interstitial/alveolar pattern Interstitial/alveolar pattern

(focal/multifocal), nodules(focal/multifocal), nodules due to granulomas, thromboembolism, due to granulomas, thromboembolism,

secondary disease (e.g. pneumonia)secondary disease (e.g. pneumonia) Intraluminal massesIntraluminal masses

Pansy Ellis Acc # 34921

ReferencesReferences1. 1. Caswell JL, Williams KJ. Caswell JL, Williams KJ.

Infectious diseases of the Infectious diseases of the respiratory system. In: Maxie respiratory system. In: Maxie MG, ed. MG, ed. Jubb, kennedy, and Jubb, kennedy, and palmer’s pathology of domestic palmer’s pathology of domestic animals vol.2.animals vol.2. 5 5thth ed. Elsevier, ed. Elsevier, 2007;645-653.2007;645-653.

2. 2. Maxie MG, Robinson WF. Maxie MG, Robinson WF. Diseases of the cardiovascular Diseases of the cardiovascular system. In: Maxie MG, ed. system. In: Maxie MG, ed. Jubb, Jubb, kennedy, and palmer’s pathology kennedy, and palmer’s pathology of domestic animals. vol.3. of domestic animals. vol.3. 5th 5th ed. Elsevier, 2007;87-89.ed. Elsevier, 2007;87-89.

3.3. Zajac AM, Conboy GA. Zajac AM, Conboy GA. Veterinary clinical parasitology. Veterinary clinical parasitology. 77thth ed. Blackwell Publishing, ed. Blackwell Publishing, 2006;4-10.2006;4-10.

4. 4. Lamb CR. Canine and feline lung. Lamb CR. Canine and feline lung. In: Thrall DE. In: Thrall DE. Textbook of Textbook of veterinary radiology. 5th ed. veterinary radiology. 5th ed. Saunders, 2007;591-598.Saunders, 2007;591-598.

5.5. Boag AK, et al. Radiographic Boag AK, et al. Radiographic findings in 16 dogs infected with findings in 16 dogs infected with Angiostrongylus vasorumAngiostrongylus vasorum, , Vet. Vet. Rec.Rec. 2004(154);426–430. 2004(154);426–430.