Nematodes VII: Ascarids Flashcards
What are the ascarids in poultry?
Ascaridia galli
Heterakis gallinarum
What is the DH of Ascaridia galli?
Birds in Order Galliformes
Ducks, other waterfowl
What is the PH of Ascardia galli?
Earthworm
What is the DH of Heterakis gallinarum?
Birds in Order Galliformes
Ducks, other waterfowl
What is the PH of Heterakis gallinarum?
Earthworm
What are the signs of Heterakis gallinarum due to?
Histomonas meleagridis
What is most pathology of Heterakis gallinarum due to?
Histomonas meleagridis
What is Heterakis gallinarum/Histomonas meleagridis most important in?
Turkeys
What is the pathogenesis of Heterakis gallinarum?
Pale circular lesions in the liver
Typhlitis (inflammation of cecum)
Vector of Histomonas meleagridis (protozoa)
Most pathogenic in turkeys
What is the main way to control Ascaridia galli and Heterakis gallinarum?
Management
Are any chickens resistant to Ascaridia galli or Heterakis gallinarum?
Older chickens are possibly resistant
What is the DH is Ascaris suum?
Swine
What is the PH of Ascaris suum?
Dung beetle
Earthworms
What is the infective stageof Ascaris suum?
L3 and the egg
Where does Ascaris suum migrate?
Liver
Lungs
Small intestine
What is the pathogenesis of Ascaris suum in the liver?
Cellular destruction
Interstitial hepatitis
Localized fibrotic areas; reaction to larvae; “milk spots”
What is the pathogenesis of Ascaris suum in the lungs?
Hemorrhage, bronchitis, edema
Pneumonia in young pigs
What is the pathogenesis of Ascaris suum in the small intestine?
Catarrhal enteritis
Adult worms interfere with nutrition
Obstruction or perforation
What are clinical signs of Ascaris suum?
Coughing
Rapid shallow breathing called “thumps”
What is the DH of Parascaris equorum?
Equids
What is the PH of Parascaris equorum?
There is not one
What are clinical signs of Parascaris equorum due to?
Different stages
What is the peak prevalence of Parascaris equorum?
4 months of age, and it decreases at 6 months
What are the DH of Toxascaris leonina?
Canids
Felids
Wild canids
What is the PH of Toxascaris leonina?
Rodents
What is distinctive about the Toxascaris leonina life cycle?
No somatic migration, but it still ends up in the small intestine
What is the Toxascaris leonina pathogenesis?
Toxascariasis
Not highly pathogenesis because there is not somatic migration, so no mammary or transplacental transmission
This infection is very rarely reported in humans
What are the transmission routes of Toxocara cati?
DH ingests L3 in egg ---migration of larvae DH ingests PH ---no migration Transmammary ---infection only when queen is lactating ---NO TRANSPLACENTAL
What is the pathogenesis of Toxocara cati?
Mechanical damage to SI
Interference with nutrition
Obstruction of SI
What are the transmission routes of Toxocara canis?
- DH ingests L3 in egg
- PH ingests L3
- L3 ALD; re-activate
- –Transmammary
- –pups infests L3. L4, adults in SI - L3 ALD; re-activate
- –Transplacental
- –L3 to stomach. L4, adults in SI
What is the most important transmission route of Toxocara canis?
Transplacental
What is Baylisascaris procyonis?
Ascarid of raccoons
Occasionally found in dogs
Midwest, NE West coast, emerging in SE
What is the direct transmission of Baylisascaris procyonis?
Yound raccoon ingests egg with L2; hepatopulmonary migration
What is the indirect transmission of Baylisascaris procyonis?
PH: small mammals, birds
Older raccoons ingest PH
What are the accidental hosts of Baylisascaris procyonis?
Humans
Why is Baylisascaris procyonis a concern?
Raccoon latrines
Children playing
Dog can acts as a DH
Can spread near people
What are the 2 major forms of Toxocariasis that cause it to be a public health concern?
Visceral toxocariasos (VT), also called visceral larva migrans (VLM) Ocular toxocarisis (OT), also called ocular larva migrans (OLM)
What is the pathology of the DH with Baylisascaris spp?
Usually no significant lesions
What is the pathology of other hosts with Baylisascaris?
Mechanical damage to tissues; granulomas
Brain and spinal cord lesions
Lung damage from migration
