Nematodes Flashcards
Which sp of Ancylostomatoidea is most & least zoonotic?
A. braziliense (most)
Uncinaria (least)
Most common MOI for A. canimum which can cause severe issues in puppies?
Transmammary
Common name for Ancylostomatoidea?
Hookworms
Common signs of Ancylostomatoidea?
anemia & diarrhea
Which Ancylostomatoidea causes the least path? most path? (cats & dogs)
least: uncinaria- cutting plates
most: brazillense - teeth
Define resistance:
when there is a greater freq of ind w/in a pop able to tolerate doses of a medicine than in a normal pop of the same species and is heritable (due to drug exposure)
T/F: worms can survive drug tx prior to ever being exposed
T/F: drug exposure does not select for inherited resistant genes
T/F: The exposure of the drug to an already resistant worm does not change the levels of resistance genes in a population
True
False: drug exposure does indeed select for worms that carry the resistant gene to the drug
False: exposure of the drug to an already resistant worm population WILL increase the levels of resistant genes within that population
How to avoid resistance?
Decrease the anthelmintic use
Decrease parasite exposure to anthelmintic
Treat ONLY animals that are causing the problem or suffering from it (~20% of the population are norm the issue)
Refugia
McMaster test; consider the imp of the animal/ its job & the OK parasite load before Tx
Ultimately resistance can only be slowed down & never stopped
Refugia?
Parasites not exposed to anthelmintic
In environment/ in animal
DESTROYING REFUGIA = creating resistance
Another name for Small Strongyles?
Cyathostomins & all horses have them | imp of only tx OSIS & not ASIS
Predilection site for Strongyles?
Larval sites?
LI
Large Strongyles: migrate to organs
Cyathostomins: encyst w/i LI wall
DH/FH for Strongyles?
Horses
Of the large Strongyles: name the sp, ppp, path & predilection site.
S. vulgaris (6m) cranial mesenteric arteries/ clots & death
S. equines (9m) liver & abdominal tissue / anemia
S. edentatus (11m) liver & pancreas / anemia
Which Strongyles is the most resistant?
Cyathostomins; resistant to all drug classes / short PPP & massive pasture buildup
Cyathostomins: PPP & Path?
1-4 months
Larval CyathostominOSIS
Larval Emergence of L4 from encysted mucosa in the LI
Hypobiosis (~2.5 years) through winter & emerge in spring
chronic D/ prot loss/ colitis
There is a 4-5 wk old foal with diarrhea who’s fecal float showed Cyathostomin eggs, what is the most likely cause?
Caprophagia. Egg was ingested therefor no further dev of the egg / no OSIS/ not the source of the diarrhea
Forms of diagnosing Ancylostomatoidea;
Fecal Flotation if PPP allows
Clinical signs if less than PPP
Culture L3 if needed dev on location
Diagnosing & prevention of Cyathostomins & L.Strongyles:
Fecal Float (McMaster), Culture L3, Ultrasound, arteriography for migrants | Necropsy*- for adults
Tx high shedders & suffering from inf, clean up feces, mix grazing (use another animal to act as a vacuum), & donnot overstock // DONOT TX ALL bc resistance
Nodular or pimply worm:
Oesophagostomum
What are the FH/DF of Oesophagostomum?
Cattle, sheep, goats, & pigs
Predilection site , PPP, & path of Oesophagostomum?
LI; 3-8wks (PPR), L4 arrests and causes nodules in LI/SI = immune rxn instead of the prev of larvae development; low egg count in fecal floats bc L4 causing Dx
Chronic infection in older animals = accumulation of parasite load
Ruminants: Anorexia & diarrhea
Sow: anorexia, wt loss, dec. milk prod.
Forms of diagnosing & treatment of Oesophagostomum:
McMaster/ float / Culture L3 / Necropsy*
Deworm & Selective Tx
Animals do not dev strong immunity to infection;
Difficult to control
Oesophagostomum with what other parasite causes Poor sow syndrome?
Hyostongylus rubidus
A young bird presents for asphyxia, a fecal float shows a typical strongyle egg that is operculated, what is your primary differential? how was this bird most likely infected?
Syngamus trachea with predilection site of the trachea/ lungs
Ingestion of the PH earthworm
What is the common name for Syngamus trachea?
Gapeworm
In a necropsy of a wild fowl, there is a parasite in the trachea of the animal that is in the shape of a “Y”. What is the parasite and what would have been the best way to diagnose it?
Syngamus trachea & fecal float to find the eggs
Which group of animals would you most expect to see clinical signs with Oesophagostomum?
Cattle 2/3 years old
Parasites that cause Marocoon leather ?
Hyostrongylus rubidus in pigs &
Ostertagia ostertagi in cattle
Main pathology with Ostertagia ostertagi? Type 1? Type 2?
L3 encyst in abomasum to develop into L5 and then emerge causing damage.
T1: Summer “iosis”
Calves with no immunity can have a gradual increase in parasite load which causes watery diarrhea;++ eggs in feces; +Morbitity/ - Mortality
T2: Winter “iosis”
Calves have arrested L4 then have synch emergence; more likely to have bottle jaw; -Morbitity/ +Mortality
Diagnosing and treatment of Ostertagia ostertagi?
McMaster (T1: ++eggs/ T2 low - no eggs), Clinical Signs, Grazing Hx, Culture for L3 (this can be used for prev to id the load before emergence), Plasma Pep lvls
Necropsy*
% adults to larva high in T1 & low in T2
Type 1: deworm & safe pasture
Type 2: Effective deworm against L4 & adults; safe pastures
Development of immunity with age
What is the number 1 killer in cattle? What parasite similar to this one and it is present in the abomasum of sheep and goats but is not as severe?
Ostertagia ostertagi // Teladorsagia circumcinta
Sheep/ goats: Wt. loss, intermittent diarrhea (NOT watery), signs of PPR, & there are nodules similar to those found in Ostertagia ostertagi in the gut. Primary differential? How would you diagnose and treat this parasite?
Teladorsagia circumcinta // McMaster, Clinical Signs, Grazing Hx, Culture for L3 (this can be used for prev to id the load before emergence), Plasma Pep lvls
Necropsy*
Resistance is present so deworm accordingly and create safe pastures.
A pig presents with anemia & in appetence. Upon necropsy you find mucosal hyperplasia (Moroccan leather) & nodules (with thin red worms) forming in the stomach. What would have been your primary differential and how would you diagnose/ treat?
Hyostrongylus rubidus (stomach worm) Eggs in fecal exam (PPR) but cannot diff from Oesophagostomum/ Culture 4 L3
Deworming is effective, pasture management & timing of tx
What pigs would be most likely affected by Hyostrongylus rubidus?
Mostly in outdoor pigs that are around grass,
What is FAMACHA?
A test to see the severity of Haemonchus contortus infection. Sheep and goats must already test positive for this parasite.
Two parasites that have the “Barber pole” appearance?
Haemonchus contortus (sheep & goats) & Haemonchus placei (cattle)
A young sheep/ goat present to you with acute hemorrhagic anemia, bottle jaw, lethargy and at necropsy you fine a worm in the abomasum. What is this worm? What does this worm look like? how can you test for it? how can you prevent it?
Haemonchus contortus, barber pole appearance
McMasters, clinical signs, & culture of L3
Resistance! Tx only the high shedders and ones suffering from inf.
T/F Haemonchus placei is the most common parasite in cattle and causes the most mortality.
False. Ostertagia ostertagi
but Haemonchus contortus is the number one killer and most common parasite in sheep and goats
How would Haemonchus placei present itself in an older animal?
chronic haemonchosis (wt loss & weakness) in older animals whom develop some immunity wt loss & weakness
T/F Haemonchus placei is found in cattle and they are more common in causing hyper acute problems.
False. they cause more Acute/ chronic inf > hyper acute
What are the DH/FH of Trichostrongylus spp? and where are they found?
It is host specific but Cattles, sheep, goats,& horses
found in abomasum/ stomach & SI
Trichostrongylus spp. host is showing signs of?
Heavy inf = diarrhea but with low inf can be found in malnourished or stressed animals
Diarrhea is not normally a sign caused by this parasite more likely due to stress
Parasite that infects SI of cattle, sheep, & goats. Looks like a watch spring & can cause watery diarrhea when host is stressed.
Cooperia spp.
Cooperia spp. is most common in what host? what can be done for tx & prevention?
Weanling cattle: 6m-older PPP2-3 wks
McMaster, Culture for L3, necropsy
Resistance but deworm accordingly
Tx: environment & animal husbandry
Name all 3 Dictyocaulus spp. and important characteristics to the DH.
D.filaria: sheep & goat infections but uncommon / young animals
D. arnfieldi: donkey, adapts, all ages, eggs with L1/ or just L1 in feces
Horses are not adapted; rarely reach sex maturity so no L1 to diagnose; fatal 2 horse
D.viviporous: cattle dev immunity w/ age
Common name is “Lung worm” / what is their LC?
Dictyocaulus spp.
Migration via blood from intestines after L3 ingested; L1 are coughed and passed in feces
Predilection site: LUNGS
Best way to diagnose a horse with possible D. arnfieldi? how to treat/ prevent ?
BAL - barman for L1 is not ideal bc immature stages in horse rarely hit sexual maturity so no L1 will be prod
Don’t share pastures b/n donkeys and horses! Deworm
Pasture management and avoid endemic pastures
Besides D.Arnfieldi, how can we diagnose & treat the other sp?
Clinical signs
Endemic area
Baermann- straight tail for L1
Deworm
Pasture management and avoid endemic pastures
D.v dev immunity with age/ Post tx syndrome is a big prob
D.f cough, unthriftiness
D.a adapted, little/ no clinical signs unless in horses / all ages
Clinical Signs associated with Dictyocaulus spp.
Coughinging.
Larval migration = no signs
Prepatent: larvae dev 2 adults in lungs = alveoli’s/bronchitis
Patent: adults in lungs= bronchitis/ pneumonia from death of worms & if dewormed
Post tx syndrome: recovery 1* D.viviparus “post patent parasitic bronchitis” / bc parasite in lungs, immune rxn occurs causing more issues/ dx
The “long neck bankrupt worm” causes issues in what host?
Sheep (Mostly concerned) , goats, cattle
L1-L3 in egg & can live for 2 years as L3 & L3 is infective
Egg req freezing & thaw periods
Nematodirus battus / HUGE EGGS TO HOLD ALL 3 STAGES
What is the predilection site of Nematodirus battus
and what is its pathology? and treatment?
SI
Egg req freezing & thaw periods = synch emergence ~Spring; lamb2lamb*they lay te eggs in winter, the emerge to be ingested by a lambs an L3 in spring
Larval stages cause severe diarrhea; 30% death; sudden onset
Clinical signs during PPP, Dec egg count; check grazing Hx of parasite in area, necropsy: dehydrated bodies / Mild catarrhal enteritis
Tx; avoid infected pastures used in prev spring, propholactic Tx (tactical tx)
Resistance is a serious issue concerning which types of animals?
Livestock
From livestock, what animals are doing better / worse with resistance issues?
Horses & cattle (good but starting to show problems)
Sheep & goats (serious problems)
Any animal that has worms that have not been exposed to treatment, or eggs in the pasture with no treatment, or the proportion of worm population that has not been selected for drug treatment is considered?
Refugia
What is selective tx?
treating only some animals dependent on a criteria.
clinical signs
FEC > than a number
etc (FAMACHA)
Why is fecal egg count important?
Identify high sheeders- one contaminating pasture
identify ones suffering from dx
high shed does not = dx (some parasites just produce more eggs)
Calculation for efficacy?
[(pre tx FEC) - (post tx FEC) / (pre tx FEC) ] x 100 = efficacy of anthemintic
What does resilience look like in a host with parasite load?
animal 1 = FEC 1000 eggs = sick
animal 2 = FEC 2000 eggs = NOT sick (resilience) BREED THIS ONE WITH SICK ONE TO PASS GENES!
What is strategic tx? what is tactical tx?
strategic: tx at specific times, entire herd is treated based on seasonal prevalence of parasite, livestock management but this leads to a more RAPID resistance / decreased refugia
tactical: tx when a large number of worms are expected (after rains and warms weather), everyone is treated, leads to more rapid resistance and decreased refugee. unfortunately it is sometimes necessary to avoid huge loss. gg
What kind of diagnostic test would you do for Metastrongylus spp?
Fecal float w/ L1 in egg
Equine, sheep, goats, equids are noted to present neurological signs in a pasture where white tailed deer are commonly seen, how do you test for this parasite? what is it?
Parelaphostrongylus tenuis “meningeal worm”
Diag with clinical signs and presence of deer bc Host are abhorrent ones and the adult stage of the parasite never develops
HIGH mortality
Muellerius spp. is found in which DH/FH and what are its clinical signs, diagnosis, & tx?
Sheep & goats
“lead shot” in lungs
Pneumonia rare in sheep
Heavy inf in goats = +serious
Dewormers eff but control is hard bc IH in longevity of egg
Bearmann- s shape tail L1
How do she/ goats get infected with Muellerius spp?
Ingestion of infective L3 in a IH mollusk
A young group of piglets whom live outside presented with a cough. You do a fecal float that shows an irregular shaped egg with an L1 inside of it. What is the parasite? how do you prevent it? and how did the pigs get it?
Metastrongylus spp.
Hard to control bc IH earthworms = long lasting expos.
Young pigs (4-6m) affected++
Multiple dewormers ok’d
What are the names of the Metastrongyloidea seen in dogs? cats?
Filaroides (oslerus) osleri (DOG) Aelurostrongylus abstrusus (cat)
An outdoor cat that normally likes to hunt presents with a chronic cough. Primary differential? How would you diagnose and how this this cat get the parasite?
Aelurostrongylus abstrusus
Baermann for L1 - kinked tail
Ingestion of the IH (mollusk) or PH (bird, rodent, frog whom ingested the IH)
What is the predilection site of Aelurostrongylus abstrusus?
Lungs & creates Small-gray nodules
Show from greatest to least, immunity in sheep, cattle and goats.
Immunity: cattle > sheep > goats
Female dog living in a kennel/breeding facility is showing signs of Dry cough; resp distress; anorexia & emaciation. What is the parasite and how would you diagnose?
Filaroides (oslerus) osleri
Centrifuge or Baermann- kinked tail for L1
Filaroides (oslerus) osleri can be dangerous for a puppies who’s mothers are infected why?
parasite is transferred by sputum so when mom licks the pups she can transmit the parasite & although there are some dewormers that are available, there is resistance present with all Metastrongyloidea
What gross characteristics can you see with Filaroides (oslerus) osleri ?
Nodules in lungs with scope
