Parasitology: Faecal Egg Count

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What is the characteristic shape of Trichostrongyles eggs?

Barrel shaped with bipolar plugs

Round and rough pitted outer shell

Oval and thin shelled (correct)

Elongated and tapering ends

Which parasite has eggs with a smooth brown shell wall surface and bipolar plugs?

Trichuris vulpis (correct)

Dirofilaria immitis

Ancylostoma spp.

Strongyloides stercoralis

What is the size range of Ancylostoma spp. eggs?

72–90 × 32–40 μm

295–325 × 5–7.5 μm

65–90 × 34–50 μm

52–79 × 28–58 μm (correct)

Which parasite has microfilariae in the blood with gently tapered heads and relatively straight tails?

Dirofilaria immitis Signup and view all the answers

What is the characteristic feature of Hookworm Ancylostoma spp. larvae?

Deep buccal cavity Signup and view all the answers

Which parasite has eggs that are the largest among ruminant trichostrongles?

Nematodirus spp. Signup and view all the answers

What can affect the concentration of eggs per gram of faeces?

The daily volume of faeces produced by the host Signup and view all the answers

Why may some eggs not float well in solutions of lower specific gravity?

They are heavier than others Signup and view all the answers

Which of the following parasites produces many more eggs per day than others?

Haemonchus Signup and view all the answers

What can make it difficult to distinguish between eggs of different species?

The similarity in appearance of eggs from different species Signup and view all the answers

What is a characteristic of nematodes?

They have a complete digestive tract Signup and view all the answers

What is a characteristic of male nematodes?

They have a curved posterior end and copulatory structures Signup and view all the answers

What is the purpose of leaving the counting chamber to stand for 5 minutes?

To allow the eggs to float to the surface and the debris to settle at the bottom Signup and view all the answers

What is the calculation to determine the number of eggs per gram of faeces?

Count the number of eggs within the grid of each chamber and multiply by 50 Signup and view all the answers

Why is it important to process only a few samples at a time?

To prevent the flotation fluid from destroying delicate eggs Signup and view all the answers

What is a factor that can influence the daily output of eggs by fertile female worms?

Host physiological factors such as stress or lactation Signup and view all the answers

What can affect the recognition or numbers of helminth eggs found in a faecal sample?

Number of factors, including host-physiological factors and chemotherapy Signup and view all the answers

What is the purpose of examining the subsample of the filtrate under the compound microscope?

To identify the type of parasite present Signup and view all the answers