Parasitology

Question 1

Which one of the following ectoparasites normally spends its entire life cycle on the chicken, causing feather damage, anemia and irritation?

A - Neocnemidocoptes gallinae
B - Dermanyssus gallinae
C - Northern fowl mite
D - Trombicula alfreddugesi
E - Red chicken mite

Answer 1

C

The Northern Fowl Mite (Ornithonyssus sylviarum). The Northern Fowl Mite remains with its host between blood meals, while the Chicken Mite (Dermanyssus gallinae) feeds only at night and drops off the host during the day. Therefore, you are likely to find the Northern Fowl Mite on the chicken during the day in the vent area, whereas the Chicken Mite is found in the chicken house during the day.

Question 2

Which choice is associated with osteosarcoma and hypertrophic osteopathy?

A - Spirocerca lupi
B - Coccidioidomycosis
C - Habronema spp.
D - Blastomycosis
E - Ollulanus tricuspis

Answer 2

A

A disease of dogs in the Southern U.S. and tropical climates, Spirocerca lupi (esophageal worms) make reactive granulomas of variable size in the esophageal, gastric or aortic walls. Large granulomas may become neoplastic (osteosarcoma, fibrosarcoma).

Typically asymptomatic, but large granulomas can cause esophageal obstruction.

Spirocercosis may also lead to aneurysm in the thoracic aorta or an ossifying spondylitis of the posterior thoracic vertebrae.

Question 3

Which parasite can cause cutaneous larva migrans in people?

A - Habronema spp.
B - Trichuris spp.
C - Spirocerca sp.
D - Trichostrongylus spp.
E - Ancylostoma spp.

Answer 3

E

Hookworms (Ancylostoma spp.) may cause cutaneous larva migrans in people.
Note that Roundworms (Toxocara spp., Toxasacaris spp.) are also zoonotic, causing visceral and ocular larva migrans in people.
In dogs, Whipworms, Trichuris spp. are associated with a hypoadrenocorticism-like syndrome (hyponatremia, hyperkalemia, azotemia, metabolic acidosis). Whipworm infection has been suggested as one cause of cecocolic intussusception.