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63 Cards in this Set
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- large (<18 cm) roundworm in SI of dog - efficient transplacental tx |
Toxocara canis |
- specialist (vertical tx) - thick shell, pitted egg w single cell in feces - Tx: slow kill to avoid blockage |
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Toxocara canis life cycle (pups) |
- direct (no IH) - some hypobiotic larvae mobilized by pregnancy: enter liver & lung of fetus and finish TM - some transmammary tx (rare) |
- fate of infected larvae in host depends on age and immune status: < 3 mo = TM (PPP = 4-5 wk) 3-6 mo = increasing SM 6 mo+ = only SM |
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Toxocara canis life cycle (dogs) |
- bitch infected by ingesting pup feces (thus deworm both) - ingestion of PH w larvae = short-lived patent infection (no migration) |
- fecal oral - PH prey |
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Toxocara canis pathogenesis (intestinal phase) |
Heavy infections: - unthriftiness, poor growth, dry skin, dull coat - painful abdomen = gait & behaviour - cachexia w high density Very heavy infections: - vomit worms/worms in feces - death prior to patency |
- mainly light infections but if it's heavy, it's bad... |
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Toxocara canis pathogenesis (migration phase) |
- lots of migrating larvae = eosinophilic gastroenteritis or lung problems - dead larvae = focal lesions - humans = OLM or CLM |
- usually non-pathogenic but sometimes (think of where they migrate)... |
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- large (10 cm) roundworm in SI of cats |
Toxocara cati |
- specialist (vertical tx) - cervical alae (cuticular extension) = arrowhead - thick-shelled, pitted eggs w single cell in feces |
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Toxocara cati life cycle |
- mainly transmammary tx - kittens = TM - cats = SM - ingestion of PH = short-lived infections in cats |
- the other trans tx - kittens vs cats - PH prey |
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Toxocara cati pathogenesis |
Moderate burden: - vomit Heavy burden (rare): - unthriftiness, diarrhea |
- not as bad as T. canis - cats vomit for pleasure - moderate vs heavy burden |
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- infects both dogs & cats (generalist) |
Toxascaris leonina |
- not as common as Toxocara - same size as T. cati but no cervical alae - smooth shell, frilly inside - single cell does not fill egg |
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Toxascaris leonina life cycle |
- direct & simple - primarily oral tx (no vertical) from egg or PH - eggs release L3 in gut = MM - PPP = 2 mo |
- generalist - no TM |
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Toxascarais leonina pathogenesis |
- not as pathogenic as Toxocara - heavy burdens rare |
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- heavy-bodied (<50 cm) white roundworm in SI of equids |
Parascaris equorum |
- thick sticky protein coat on eggs (VERY HARDY) - no vertical tx |
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Parascaris equorum life cycle |
- oral tx of infective egg (L3) with feed or water - L3 penetrates SI, TM via liver and lung in younger equids - return to SI and grow to adult - PPP = 10-12 wk |
- no vertical tx |
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Parascaris equorum pathogenesis |
Clinical signs in young equids: - unthrifty, appetite loss - hypoalbuminemia = decrease oncotic P = edema & swelling - heavy burden = colic - TM = coughing, snot |
- young vs old animals - "summer colds" |
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- heavy-bodied (<50 cm), white roundworm in SI of humans and pigs |
Ascaris lumbricoides |
- thick protein coat on eggs - most common human helminthic infection - primarily in tropics/subtropics and areas with poor sanitation - males smaller |
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Ascaris lumbricoides life cycle |
- oral tx of infective egg - L3 penetrates SI, TM via liver and lung - return to SI and grow to adult - PPP = 6-8 wk |
- typical roundworm LC |
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Ascaris lumbricoides pathogenesis |
- can stunt growth in children - TM = "milk spots" on liver - heavy = occlude biliary tract, oral expulsion - lung phase of TM = Loeffler's syndrome |
- usually asymptomatic, but migration (GIT, lungs) can cause problems... |
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- heavy-bodied (<40 cm), white roundworm in SI of pigs (and humans) |
Ascaris suum |
- males smaller - thick protein coat on eggs - similar to Ascaris lumbricoides |
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Ascaris suum pathogenesis |
- "milk spots" on liver (condemn) - lung phase of TM = pulmonary hemorrhage & edema - primarily subclinical effects (enteritis = slow growth) |
- similar to A. lumbricoides |
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- heavy-bodied (<10 cm), white roundworm in SI of chickens, pigeons and turkeys |
Ascaridia galli |
- smooth shell egg - problem for layers and turkeys (not broilers due to short life) |
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Ascaridia gallum life cycle |
- oral tx of infective egg - L3 hatches, enters SI wall - L3 molt to L4 - L4 re-enters lumen, molts to adult - PPP = 30-50 d |
- direct LC - no extra-intestinal migration |
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Ascaridia gallum pathogenesis |
- MM = hemorrhage/diarrhea - decreased production - low mortality |
- due to intestinal MM |
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- slender (4-15 mm) roundworm in ceca of chickens, turkeys, etc. |
Heterakis gallinarum |
- cecal worm - thick, smooth egg shell - true IH for Histomonas meleagridis |
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Heterakis gallinarum life cycle |
- oral tx of infective egg - larvae hatch, migrate to cecal mucosa - re-enter lumen, 2 molts to adult - PPP = 24-30 days |
- direct LC - similar to Ascaridia galli except cecal worm |
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- large roundworm (<20 cm) infecting raccoons (and dogs) |
Baylisascaris procyonis |
- thick smooth shell egg - short-lived infections in dogs - zoonotic threat (in PH) |
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Baylisascaris procyonis significance |
- zoonotic threat to mammals - VLM (in brain!) = neuro - long period for eggs to become infective so clean up raccoon feces |
- raccoon latrines can be a problem... - some fatal cases! |
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- the more serious human hookworm |
Ancyclostoma duodenale |
- note the teeth - common in warm, moist areas - common infection in humans - sucks blood (pica = increase tx) |
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- the less serious human hookworm |
Necator americanus |
- note the plates - common in warm, moist enviro - common human infection - sucks blood (pica = increase tx) |
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Human hookworm life cycle |
- eggs >>>L3 in feces/soil - filarid L3 penetrates skin - TM ultimately to SI - mature to adults, prod eggs *A. duodenale larvae can undergo SM - transmammary tx* |
- infect from the soil - why A. duodenale is more serious |
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Human hookworm pathogenesis (caused by adult worm) |
- blood loss at attachment site - Fe-def anemia +/- cardiac complications - inflamed gut leaks protein = hypoproteinemia = abdominal edema |
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Human hookworm pathogenesis (caused by larvae) |
- "ground itch" during penetration by L3 - respiratory symptoms during pulmonary migration of larvae |
- IR mediated symptoms |
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- stout hookworm in dogs with 3 large pairs of teeth |
Ancyclostoma caninum |
- bend in body at buccal cavity - dark red if filled with blood |
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- thin-shelled, morulated (<70 um) egg in dog feces |
Ancyclostoma caninum |
- typical strongylid egg |
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Ancyclostoma caninum life cycle (dogs...or man) |
- direct - morulated eggs in feces>>>L3 - L3 penetrates dog (or man) skin - SM, hypobiosis - reactivate (e.g. in lactation) - ingestion of L3 = MM (patent) |
- penetration vs ingestion - zoonotic threat (CLM) - enviro effect - PPP = 3-4 wk |
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Ancyclostoma caninum life cycle (puppies) |
- transmammary tx - TM |
- PPP = 2.5 wk |
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Ancyclostoma caninum pathogenesis |
- anemia & hypoproteinemia (= edema) - enteritis (= melena, emaciation) - acute (50-100 worms) = bleed out before patency |
- blood suckers - heavy loads are fatal |
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- northern hookworm in dogs and cats with cutting plates |
Uncinaria stenocephala |
- note the plates and DHs |
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- thin-shelled, morulated (>70 um) in dog and cat feces |
Uncinaria stenocephala |
- notes size |
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Uncinaria stenocephala life cycle |
- morulated eggs in feces>>>L3 - L3 = hardy, freeze-tolerant - L3 ingested - no extra-intestinal migration |
- direct - PPP = 2.5 wk |
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Uncinaria stenocephala pathogenesis |
- anemia & hypoproteinemia - mild enteritis |
- less pathogenic than Ancyclostoma (not as strong a blood sucker) |
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- lungs of sheep and goats causing alveolar rupture |
Muellerius capillaris |
- metastrongylid nematode |
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Muellerius capillaris life cycle |
- ingestion of IH (oral tx) - migrate to alveoli and terminal bronchioles - L1s shed in feces +/- resp discharge |
- indirect - DH = goats & sheep (ruminants) - IH = snails & slugs (not PHs) - PPP = 6-10 wk |
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Muellerius capillaris pathogenesis |
- alveolar rupture - focal interstitial pneumonia (more serious in goats ~ concurrent infection) - some granuloma formation - some areas may calcify |
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2 species of lungworm infecting domestic and wild canids |
Filaroides (hirthi) & Oslerus (osleri) spp. |
- F & O - larvae detected in sputum and via Baermann technique |
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Filaroides & Oslerus life cycle |
- eggs hatch in bronchi & trachea - L1 (infective) shed in feces - L1 ingested, TM - adults in trachea/bronchi (O) or bronchioles/alveoli (F) |
- direct - PPP = 10 wk (O) and 5 wk (F) |
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Filaroides & Oslerus pathogenesis |
- F = usually asymptomatic - O = nodules, bronchitis or tracheitis from released eggs/larvae + wheezing cough - heavy burden = dyspnea |
- lesions can be seen with bronchoscopy |
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Baermann technique |
Set up: tissue/gauze/funnel/flask - larvae crawl from fecal mass - definitive diagnosis based on larval morphology |
Used for diagnosing: - lungworm |
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True lungworm in deep lung of (outdoor) cats |
Aelurostrongylus spp. |
- requires IH (snail/slug) - PH = frog, rodent, lizard, bird - infects small bronchioles/alveoli - larvae have small bent tail w dorsal spine |
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Aelurostrongylus life cycle |
- larvae passed in feces infect IH - ingestion of IH - larvae migrate to lungs - adults in terminal respiratory tract or lung parenchyma |
- indirect - IH = snail or slug - PH = frog, rodent, lizard, bird (most common source of infection) - PPP = 5-6 wk |
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Aelurostrongylus pathogenesis |
- adults, eggs, larvae = focal pneumonia w granulomas - heavy burden = chronic cough + dyspnea |
- diagnosis: larvae in sputum or w Baermann technique |
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True lungworm in small bronchioles & alveoli of canids & raccoons |
Crenosoma spp. |
- anterior cuticle has prominent folds (crenations) - requires molluscan IH - locally relevant |
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Crenosoma life cycle |
- L1 in feces infect IH - DH ingests IH w infective L3 - L3 migrates to lungs - adults in bronchi & bronchioles |
- diagnose w Baermann - PPP = 19 d |
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- the large, migratory equine bloodworm |
Strongylus vulgaris |
- dramatic extra-intestinal migration - adults feed on cecum and colon - buccal cavity is deeper than it is wide |
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Strongylus vulgaris pathogenesis |
- developing L4 migrate in the cranial mesenteric arteries for <2 mo - arteritis & thrombosis at site of development (ileocolic artery and branching arteries) |
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Strongylus vulgaris clinical signs |
- acute arteritis = pyrexia, anorexia, colic, death - chronic = intermittent colic (impaired blood flow - emboli or inflammatory vasoconstriction +/- nerve damage) |
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- non-migratory strongyles |
Cyathostomes |
- in equids - buccal cavity is wider than it is deep |
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Cyathostomes life cycle |
- larvae dev'p in eggs, hatch - L3 ingested, MM - hypobiosis in mucosa in some sp., overwinter on pasture in others |
- PPP = 5 wk to >20 mo |
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Cyathostomes pathogenesis (larvae) |
- nodules around encysted larvae impedes gut motility = inappetence, poor ADG - reemergence = inflammation, edema, ulceration (ALC) - anorexia, wt loss, diarrhea, colic |
- primarily due to larval mucosal migrations - ALC = acute larval cyathostomiosis |
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Cyathostomes pathogenesis (adults) |
- heavy burden = non specific clinical signs (unthriftiness, digestive upsets +/- colic) - not usually fatal |
- clinical w heavy burden only |
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- strongyle in ruminants and swine |
Oesophagostomum spp. |
- pimply gut worm - typical life cycle w deep MM - prominent nodule formed during MM (hypobiosis) |
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- strongyle infecting trachea of gallinaceous & other birds |
Syngamus trachea ("gapeworm") |
- eggs operculate 2x - M & F attached in copula ('Y') |
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Syngamus trachea life cycle |
- larvae in eggs, soil or PH = infective - larvae penetrate intestines - migrate lungs>alveoli>trachea - attach to mucosa, suck blood & mate |
- various infective larval forms - predilection site is in the name - PPP = 10 d |
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Syngamus trachea pathogenesis |
Adults in trachea: - cause gasping, gaping - increase mucus production - mild anemia, reduce production - heavy = asphyxiation = death |
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