Module 1: Basic Diagnostic Concepts Flashcards
How to choose a technique?
Well, depends on the parasite. However, consider:
Host, Clinical presentation, Age of host and Exposure.
What are the common techniques?
For parasite identification
- Fecal flotation (centrifugation)
- Bearmann
- Fecal smear
- Quantification (equine, ruminants, production)
- Soil or pen ropes
- Muscle biopsy or histopath of tissues
- Sedimentation
- PCR
What is the most common technique used per the professor?
Double centrifugation flotation assay
This method has a two step proccess of water washing and suggar float.
What magnification should we use to scan a slide?
Whathever the fk u want!
Its 10X. It will take forever to scan at a higher mag.
Which parasites can cause respiratory signs on a cat?
Heart Worms and Lung Worms
Is it rare to identify larva on a flecal float?
Yes!
Almost always, you only see ova. However, sometimes you can see a larva.
Double Centrifugation
(Overview of what it is)
- Wash fecal sample and pellet eggs
- Floating the eggs
- Microscopic examination of eggs
- Specific gravity of species
Protocol for Double Centrifugation
- Mix feces (1grm) with around 7 mL of H2O (Mix well)
- Strain the mix to remove particulates (cheese cloth, metal strainer and others).
- Let the brown water precipitate
- Remove excess of water
- Add flotation solution to fecal pellet (fill up to 1mm from the top)
- Centrifuge sample
- Add a bit more solution to form meniscus
- Add coverslip
Why pay attention to the big G?
Gravity
Because of physics. Eggs typically float if the solution is 1.26 or greater in density.
Eggs are typically ( >1.0 - < 1.26 ) in density.
Where are the eggs located after the water wash step?
Because eggs are of a higher density than water, the ova should be located in the precipitate or the bottom of the sample.
Name the kids of solutions used for fecal floats?
- NaCL
- Zinc sulfate
- Sodium nitrate
- Sheather’s sugar or Sugar
Sugar holds ova for longer!
Do you dilute float solution to make more?
Hell naa mother fker! Leave that as it is! Sooo False you stupid!
Do you use hydrometer or refractometer to measure SG of solution?
Specific Gravity
Hydrometer
Used for density
Why would you use different solutions for fecal floatation?
Because sometimes, specific gravities are needed to preserve the eggs or find them.
Like everything, it depends of what you are looking for.
Centrifugation instructions
- Spin for 5 minutes (do not stop)
- Speed (400 - 1000 x g)
Fecal flotation is good for?
Nematodes Ova
Fecal flotation is not good for?
Trematodes Ova, some Protozoa “Trichomonads”, and some larval “Strongyloides”
Because eggs may be to heavy for the float density.
Baermann Test is used for?
Larval stages found in fecal samples
Baermann Test is commonly used to find?
Lungworm Infections
In cats, dogs, cattle, equids, and others.
Baermann Test requires fresh or old feces?
Freshh as fk boy!
Becasue if old, other parasite eggs can hatch
Causing a confusion if you are trying to find lungworms
Which stages if the life stages of the ova and larva are environmental stages?
Da fuk did you ask? Just trust, is L 1-3 stages that are environmental stages
Baermann Instructions
- 10 grms of feces in cheesecloth/kimwipe/wire filter
- Hang or suspend over wire
- Contact with warm water for 8 hrs or overnight
- Collect material at the bottom or centrifuge
- Examine at 4x/10x
Fecal smears are used for?
Identification of Protozoa (Giardia, trichomonads, amoebae)
Not recomended for routine fecal analysis
Fecal smears have a ____ sensitivity?
Im talking about low, low, low, low, low, low…
How to perfom a direct smear
- Small amt of feces
- Drop of saline (Not H2O)
- Mix, make sure you can read news print through the smear mix
- Cover slip
- Look for motile Protozoa
- You can stain but is not common
Fecal quantitative egg count is common in what industry?
Equine (Horse girl shit)
Fecal quantitative egg count is used for….
Evaluation of drug efficacy or parasite burden
Fecal quantitative egg count is useful for the identification of?
Strongylid type parasites
Equine: cyanthostomes and large strongyles
Ruminants: strongyles (HOTC)
HOTC- Haemonchus, Ostertagia, Trichostrongyus and Cooperia
Coccidia means?
Round protozoal stage found in feces (Cystiospora, Eimeria, Toxoplasma, Sarcocytis, Neospora, ect)
Everything including Hu-Mans can have this
Essentially Coccidia is a very broad term
Fecal quantitative egg count Rational?
The big Why!
- Who to treat in group
- Drug resistance
- Pasture management (Low count means pasture not a risk)
- Predict disease occurance (If high, probable that animals will develop disease)
Kinds of Fecal quantitative egg counts
- McMaster’s (need high numbers)
- Stoll’s (for low numbers)
- Wisconsin (for low numbers)
Fecal quantitative egg count can help to……
Determine if a treatment is succesful.
Can be dertemined if using a pre and post groups.
Fecal quantitative egg count treatment success results
- Fully efective is greater 90%
- Suspect if egg count reduction is less than 90%
- If less than 10%, Worms are resistant
Simple Sedimentation can be used for….
- Heavy ova that don’t float well
- For Flukes and some Nematodes
Simple Sedimentation Steps
- Mix 20 ml of water with 10 grms of feces
- Wait 2 minutes, save top liquid
- Wait 2 hrs for sample to sediment
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DE NADA!
