parasitology Flashcards
standard diagnostic method for most parasites. inexpensive, requires trained technicians
morphologic tests– look and diagnose
what are the sample requirements for a fecal exam
fresh (less than 3 hours old) or refridgerated sample, 3g,
direct saline smear is for what parasites
trophozoites because they move
oocyst vs cyst
oocyst- coccidia
cyst- giardia
what is the sensitivity of a direct smear
low sensitivity because there is a high chance of not trusting the negatives. some don’t float, etc
combine with other tests to improve
what fecal solution should you use on a routine exam that isnt have GI signs
sugar solution because it does not get giardia, but they should be clinically ill to diagnose giardia– zinc sulfate 1.18
how can sensitivity of a fecal exam be improved
larger sample, repeat the test, combine with other tests
how do you read combo tests based on sensitivity. what if only one test is positive
a positive is a positive in either test method. we only need one to believe its true.
how do you read combo tests based on specificity. what if only one test is negative
you need two negative tests to trust the results since there is low specificity and there could be false negatives.
how should we report fecal samples where we didnt find any eggs
no parasites seen.
what do we do a sediment test for
fluke eggs that are high density and wont float
what is a baermann test
rest feces at room temp water over night and the larvae will migrate out into the water, looking for larvae
you perform a baermann test and see larvae with a kink tail in dogs. what are you thinking
rule out coprophagy first as most kinked tailed nematodes are not in dogs.
blood smear identification are most effective when
acute infections
we have a worm we want to submit for ID. how do we transport it to the lab
in alcohol. never formalin
commonly used antibody test in small animal
heartworm in cats
toxoplasma in cats
what do we need to remember about toxo antibodies in cats
igM does not mean acute infection. can be in circulation for 12-18 months.
perform serial titers
when do we use the giardia antigen test
when there is diarrhea only. do not test asymptomatic dogs
when to perform a antigen IDEXX test
dog with clinical signs
suspect coprophagy in a dog
small fecal volume
what do we use PCR for
hemoparasites, protozoa
what is FEC for large animals for
treatment efficacy
FEC for sru
breeding
FEC for equine
we treat with the epg is >500
why cant we use egg count to make clinical diagnoses
there is no relationship between e/g and # of parasites in the animal
what do we think about FEC for coccidia
most coccidia are not pathogenic and we cant ID the pathogenic species in a FEC
what things influence fec
immunity
season
fecal consistency
luck-distribution of eggs
what is a limit of detection
the lowest egg count that can be detected
if a low egg count is suspected we need a lower LOD
when do we want to use tests with a LOD of 1 e/g
reportable diseases
when were looking for small differences
treatment evaluations
dogs
accuracy vs precision
accuracy reflects reality
precision is repeatibility of the test
most common quantitative tech
mc masters and miniflotac
which quant test has a lower LOD
miniflotac at 5 epg
which quantitative test should be used when you suspect low epg
flotec
what quant test should be used when you are running fecrt
depends on the initial test. if initial sample was in 25-50 epg then you need to run a flotec
what general reasons do we run quant tests
lookf or resistance, and FECRT
what morphologic tests do we do for large animals
none really. they all have parasites so we it isnt really helpful to ID them
baermann for lungworm larvae
sedimentation for liver flukes
most common PCR test in LA
tritrich foetus
steps to look at a fecal in unfamiliar species
use sugar solution in all feces.
figure out what broad groups the eggs belong to
look up general pathology associated with that group
+- baermann, sediment
for hook worms, when should you recheck the fecal
after 9 days but before 2 weeks. larval leak starts in 14d
what reduction percentage of hookworm is indicative of resistance
<75% reduction
