Bird Nematodes

Question 1

Nematodes of birds

Answer 1

Strongyloidea (hookworms)- Syngamus trachea

Ascaridoidea- Ascaridia galli, heterakis gallinarum

Trichuroidea (whipworm)- Capillaria sp.

Question 2

Syngamus trachea (gapeworm)

Answer 2

Host: domestic fowl and game birds

Site: trachea

Adults permanently in copula

Question 3

Syngamus trachea-routes of infection

Answer 3

1) Ingestion of L3 IN the egg (larvated L3 remains in egg)
2) Can ingest hatched L3
3) can ingest paratenic host (earthworm) containing L3

L3 penetrate SI and migrate in blood to lungs- develop to adults

Question 4

Syngamus trachea- pathogenesis

Answer 4

Migration of MANY larvae- acute pneumonia and death

Adults cause hemorrhagic tracheitis

Partial airway occlusion “gapes”- if adults are producing eggs.

Question 5

Syngamus trachea- clinical signs

Answer 5

Most severe in young birds

Depressed

Dyspneic (pre-patent)

Gasps, head shaking, cough (patent)

Question 6

Syngamus trachea- diagnosis

Answer 6

Barrel shaped egg with bipolar operculum (85-90 microns)

PM to find adult worms

Clincal signs

Question 7

Syngamus trachea epidemiology

Answer 7

Disease most common in young birds/adults are carries, but turkeys of all ages are susceptible

Most frequent in outdoor pens

Eggs are VERY resistent

Infection can arise from wild birds.

Question 8

Ascaridia galli

Answer 8

typical ascarid parasite

Host: chickens and turkeys

Site: SI

Large white worm (~12 cm)

oval egg with a smooth shell

larval stage in egg is infective

NON-migratory (no hepatotracheal migration)

not very pathogenic

Question 9

Ascaridia galli epidemiology

Answer 9

mostly a problem in young birds

older animals tend to be resistant or can be asymptomatic carriers

Deep litter housing or outdoor runs faciliate survival of eggs

Question 10

Ascaridia galli diagnosis

Answer 10

Egg difficult to distinguish from Heterakis gallinarium

Eggs are thick shelled and VERY resistant

Necropsy for adult worms

Question 11

Heterakis gallinarium

Answer 11

Ascarid but in LARGE intestine

Small white worm (~1.5cm)

Host: domestic and wild birds

Site: LI

eggs similar to ascaridia galli

non-migratory

not pathogenic

Question 12

Heterakis gallinarum- why it’s important

Answer 12

Not pathogenic in itself, but it is a vector of histomonas meleagridis (protozoan)

Causes blackhead in turkeys

Histomonas transmitted from bird to bird in heterakis egg.

Question 13

Capillaria species

Answer 13

Several different species with different life cycles

Different species have different prediliction sites: crop and oseophagus, or SI

Can be important parasites of poultry

Similar to trichuris species (same superfamily)

Question 14

Pathogenesis of capillaria

Answer 14

anterior end buried in mucosa

cause diphtheritic inflammation- sloughing off of top layer of cells

for species in SI, can be diarrhea

can have very high mortality

reduced weight gain/ egg laying.

Question 15

Diagnosis of capillaria

Answer 15

young bird most susceptible

older birds are carriers

non-specific clinical signs can appear before eggs in feces

necropsy: examine for worms

eggs in feces

parallel sides, bi-polar plus (50 microns long)- similar but smaller to trichuris egg.

Question 16

Nematodes in wild birds- grouse

Answer 16

In the UK grouse “boom and bust” years

Trichostrongylus tenuis drives these cyclic fluctuations through reducing survival and breeding

Controlled using medicated grit

Question 17

Control of bird nematodes

Answer 17

Anthelmintics to treat infection (flubendazole)

Hygiene

Clean litter between batches