Ascaridia spp. (1)

Question 1

What are the final hosts?

Answer 1

Chickens

Turkeys

Geese

Wild fowl

Birds

Question 2

What are the paratenic hosts?

Answer 2

Earthworm

Question 3

Describe adults

Answer 3

3 prominent lips

In small intestine

Females: 7-12 cm

Males: 5-8 cm

Largest nematodes in poultry

Question 4

Describe eggs

Answer 4

73-92x45-57 micro m

Thick shelled

Oval

Difficult to distinguish

Last a long time in environment

Egg with L2 infective

Question 5

Describe life cycle

Answer 5

Direct

Egg with a morula passes in feces

Reaches infective stage in 10-21 days

Egg with L2 ingested, hatches in small intestine

Larvae undergo a histotrophic phase (i.e., embed themselves into the mucosal layer of intestine)

 - Shorter in young or naive birds
 - Longer when many infective 
        - Preexisting infection
        - Bird has acquired immunity

Common in outdoor and free-range system

Question 6

What is the site of infection?

Answer 6

Small intestine

Question 7

Describe the Pathogenesis and clinical signs

Answer 7

Establishment of worms influenced by:

 - Age, sex, and diet of host
 - Size of infective dose
 - Age of eggs

Weight loss correlates with worm burden

Obstruction of small intestine

Younger chickens more seriously affected

Loss of appetite

Drooping wings

Ruffled feathers

Decreased egg production

Loss of weight

Anemia

Diarrhea

Death

Question 8

How do you diagnose?

Answer 8

Fecal flotation

Necropsy

Ascaridia egg > Heterakis eggs

Question 9

What is the common name?

Answer 9

Roundworm