Flashcards in chapter 17 - Deck (88)
Laboratory tests may not identify parasites if?
The parasite burden is low
The female is not actively producing eggs
There is no detectable stages that can be observed
Feces should be _______ and should not be older than _____ hours.
Fresh, 24 hours
Refrigerate feces to prevent ___ from _____, ___ from ___, or ____ from _____.
eggs - larvating
oocysts - sporulating
larva - changing
When taking a fecal sample from a group, ___ pooled sample per group is used.
Where should laboratory results get recorded?
In patient's medical record and in central laboratory result or log book
What is the central log book used for?
a backup to make sure tests are run, if the results are not in the book or patients record, they did not get run
What about the feces should be recorded in the central laboratory record book, as well as the animal's medical record?
color (black - digested) (red - blood)
presence of blood
presence of mucus
What should parasites be identified by?
genus and species so the vet can use proper control and treatment measures
Aged feces may contain what?
pseudoparasites picked up from the environment or nonparasitic larvae from flies that have grown after defecation occurred
What type of microscopes are used for proper identification of a parasite's larvae, eggs and oocysts?
compound microscope with 4X, 10X, and 40X objectives
Microscopes with calibrated eyepieces should be calibrated for what?
each objective for accurately measuring parasite larvae, ova, or oocysts
What is the calibration used for?
to measure the hatch marks on the ocular micrometer int he eyepiece.
When is the calibration done on the objective?
it is done at each objective power recorded and affixed to the microscope for future reference
What is the simplest method of microscopic fecal examination for parasites?
the direct smear
What is the direct smear?
a good diagnostic test for viewing the motile forms of protozoans that might be destroyed by other methods
Fecal concentration methods are preferred for identifying parasites and oocysts in the feces because?
Larger volumes of feces are used making it more likely the developmental stages will be seen if present in the feces
Fecal floatation solutions with a specific gravity of 1.2 to 1.25 are used to?
"float" parasite ova, cysts, and larvae while the fecal material sinks to the bottom of the container
The fecal solutions of choice?
are sheather's sugar solution, sodium nitrate solution, sodium nitrate solution and zinc sulfate solution.
What does it depend on as to how many different types of eggs, larvae, and cysts are able to be floated?
the specific gravity of the solution
What is fecal centrifugation is?
the method of choice for fecal flotation to float a higher concentration of ova, cysts, and larvae, and cysts are able to be floated
When is fecal sedimentation test used?
it is more commonly used to test for trematodes eggs, which are heavier than other parasite eggs and thus do not float well
What does qualitative procedures tell you?
whether parasite ova or cysts are present in the fecal sample
What does quantitative procedures do?
provide the number of ova or cysts in one gram of feces
What are quantitative procedures used for?
they are used more often in research facilities than in the vet clinic
What do Giardia trophozoites do in a fecal smear?
they swim in a jerky motion
What can be used to stain protozoan cysts on a direct smear?
modified D'Antoni's iodine or Lugol's iodine
What does cystoisospora species have when sporulated?
What does Eimeria species have when sporulated?
Cultured and identification of Nematode larvae are often referred to?
state or private diagnostic laboratories