Fecal LAB & QUIZ - Endoparasites Flashcards
Solutions for fecal floatation:
Sodium nitrate (Fecasol)
- Specific gravity
- Spectrum of purpose
- Distorting/Crystal formation
- Specific gravity:
1.2-1.25 - Spectrum of purpose:
Good all purpose! - Distorting/Crystal formation:
Forms crystal on slide
Solutions for fecal floatation:
33% Zinc sulfate
- Specific gravity
- Spectrum of purpose
- Distorting/Crystal formation
- Specific gravity:
1.18-1.2 - Spectrum of purpose:
Good all purpose, especially for protozoa - Distorting/Crystal formation:
Forms crystals but there may be distortion
Solutions for fecal floatation:
Sheather’s sugar solution
- Specific gravity
- Spectrum of purpose
- Distorting/Crystal formation
- Specific gravity:
1.25 - Spectrum of purpose:
Excellent all purpose - Distorting/Crystal formation:
Doesn’t crystalize or distort.
Needs longer incubation
How do you prepare a slide for a direct fecal smear?
Create a thin film of feces and room temp saline on a microscope slide.
You will only need a speck of feces and a drop of saline.
Mix on slide and let dry
Place cover slip (wet state) and take a peek!
Direct smear method is most useful for looking at what type of parasite?
Trophozoites! They can be discerned from the rest of the flora by their characteristic movement and appearance
According to the ACT video Identifying Intestinal Parasites, which intestinal parasite can infect puppies while still in the uterus or while nursing mother’s milk?
Roundworms (Ascarids)
What is the minimum amount of solid feces to evaluate for accurate test results?
1-2 grams
Which fecal analysis test is likely to yield the most ova recovery?
a. Direct smear
b. Sedimentation
c. Centrifugal flotation
d. Passive (simple) flotation
Centrifugal
What is a hydrometer used for in a parasitology setting?
a. Checking the temperature of flotation solutions
b. Evaluation of specific gravity of flotation solutions
c. Counting numbers of recovered ova
d. Evaluation of the barometric pressure
Evaluation of specific gravity of flotation solutions
Why is an understanding of relative parasite ova size important?
- The size of the ova may determine the best test method to use
- The size of the ova can determine slide evaluation techniques to use
- Ova may appear similar but can be differentiated based on size
T/F: The main indication for performing a Direct Smear evaluation is the suspicion of motile protozoa or larva.
True
T/F: It takes less time to spin a swing-arm centrifugal sample than to float ova passively.
True
T/F: It takes less time to spin a swing-arm centrifugal sample than to float ova passively.
True
Why are tapeworm ova difficult to recover by fecal analysis and how is this important to client education?
- Tapeworm ova are heavy so they don’t float. The owner may see tapeworm segments on the pet or feces, but the fecal test will read “negative.”
- This parasite is usually identified by visual inspection of perineal fur or feces.
- The parasite requires an intermediate host (flea) for its lifecycle, so to prevent reinfection fleas must be controlled.
Why is the maintenance of fecal flotation solutions important (i.e. how do these solutions work)?
- For parasite ova to be recovered by a flotation test, the specific gravity of the solution must be greater (i.e. “heavier”) than that of the ova. Specific solutions are best for specific ova. However, this assumes that the solutions were made correctly and are not changing over time in the bottle. Therefore, the specific gravity of the solutions should be monitored periodically after they have been made or opened with a hydrometer.
OR
- This test works by using a solution with a higher specific gravity than the ova being tested for. That way the ova will float and the debris will fall to the bottom. Now you will have a sample with less debris than a direct smear would give you!
