Nematodes: Superfamily Heterakoidea

Question 1

Superfamily Heterakoidea

Answer 1

• Ascaridia spp. & Heterakis spp.
• direct, infection by L2 in egg, PH can be involved
• large white nematodes
• avian species
• thick shelled oval egg (difficult to differentiate)
• small and lg intestine
• NOT zoonotic

Question 2

Ascaridia spp.

Answer 2

roundworms
Hosts: FH: CHICKENS; domestic and wild birds
PH: earthworms
PPP: 4 wks
ID: largest nematode in poultry, 8-12cm, eggs oval and thick shelled
Infection: small intestine
-non-migratory, histotrophic
-*younger chickens more at risk, immunity w age
CS: wt loss proportional to worm burden, competing for nutrients w host, obstruction of SI
Dx: fecal float, necropsy

Question 3

Heterakis spp.

Answer 3

poultry cecal worm
Hosts: FH: domestic and wild fowl, PH: earthworms and flies
H. gallinarum: chickens, turkeys
PPP: 24-30 days (3-4 wks)
ID: adults: 1-1.5cm (much smaller bc not as much room in SI), slightly smaller than Ascaridia spp
Infection: cecum
Path:
H. gallinarum: most common, non-pathogenic on its own, transmits Histomonas meleagridis (protozoa)…once in cecum, eats the protozoa that breach the ovaries of Heterakis and then are excreted in Heterakis eggs=parasite of the parasite is pathogenic
H. isolonche: pathogenic, causes d+, emaciation, death
H. dispar: non pathogenic
Dx: eggs in fecal exam, necropsy