Gross examination
What does a gross examination of a fecal include?
consistency, color, quality/mucus, odor, parasites
what are the 5 ways for performing a fecal examination?
fecal flotation
fecal direct
centrifugal fecal flotation
fecal sedimentation
fecal cytology
What are the 4 different flotation solutions?
sodium nitrate, sugar solutions, zinc sulfate, saturated sodium chloride solution
How much stool and solution do you need for a centrifugal fecal flotation?
about 2 grams, 10 ml solution
what are the 3 methods of fecal collection?
ground, fecal loop, gloved finger
how do you preserve a fecal sample?
refrigerate, add 10% formalin
What are you looking for when performing a direct fecal?
Protozoans, & overgrowth in bacteria
what fecal solution will form crystals and distort eggs if left out for longer than 20 minutes?
What are the 3 concentration methods of fecal examinations?
standard fecal flotation, centrifugal fecal flotation, fecal sedimentation
what technique is best for examining protozoal cysts?
centrifugal fecal flotation using zinc sulfate
What two parasites can be seen during a gross examination of stool and what does their appearance resemble?
Tapeworms - grain of white rice segments (proglottids)
roundworms- spaghetti noodles
what objective lens should you use to look for eggs or parasitic worms?
10x
What solution destroys protozoal cysts such as Giardia?
Sheathers/Sugar solutions
what solution forms crystals and distorts eggs?
saturated sodium chloride solution
What the specific gravity of zinc sulfate solution?
1.18
What might mucus in the stool indicate?
whipworms
What might you perform if you need to confirm bacteria such as clostridium?
Fecal cytology
False, higher specific gravity
which technique is best for visualizing heavy trematode ova?
fecal sedimentation
How long is a fecal sample spun for?
5 minutes
What does dark/black tarry stools indicate?
Melena, bleeding from stomach or small intestines
what are the steps for performing a direct fecal?
1. Gloves
2. microscope slide, one drop of saline/water
3. mix a small amount of feces in saline/water
4. remove chunks, make a thin layer, apply coverslip
5. Examine with diaphragm closed
6. 10X (eggs), 40X (protozoa/bacteria)
What solution should you use for a centrifugal fecal flotation?
Zinc sulfate or sugar flotation solutions
When performing a centrifugal fecal flotation what's the difference in the steps of procedure when using a fixed head centrifuge vs. a swing head rotator?
fixed head- fill tube 1/2 way, centrifuge, then fill up all the way to form meniscus, add cover slip
swing head- fill tube to top to form meniscus add coverslip, then centrifuge
What's the standard fecal floatation procedure?