Digestion & Metabolism 2: LA Common GI Parasites Flashcards
STRONGYLES…
aka…
they are the ___ ___ parasites in LA
description? (2)
PRE-PATENT PERIOD in RUMINANTS?
PRE-PATENT PERIOD in HORSES
distribution?
STRONGYLIDS/GI NEMATODES
MOST IMPORTANT
description?
1. SMALL
2. HAIR-LIKE
PRE-PATENT PERIOD in…
RUMINANTS = 2-4 weeks
HORSES = 6-18 weeks
–> MORE VARIABEL because MANY SPECIES OF STRONGYLES CAN INFECT THEM
WIDE DISTRIBUTION THROUGHOUT THE WORLD
LIFE CYCLE of STRONGYLIDS…
divided into 2 phases?
5 stages
what’s special about L3 larvae? what 3 things does it give L3 larvae?
2 phases?
1. PRE-PARASITIC = EGG to L3
2. PARASITIC = L3 to ADULT
6 stages?
1. EGG = passed in FECES
–> EPSILLOIDAL, THIN-SHELLED, MORULATED
2. L1 develops in egg and HATCHES INTO ENVIRONMENT
3. L1 –> L3 in ENVIRONMENT
4. L3 INFECTIVE stage is INGESTED DURING GRAZING
5. L3 –> ADULT IN HOST
L3 LARVAE KEEPS 2 CUTICLES, ONE KEPT FROM PREVIOUS STAGE, causing…
1. can SURVIVE up to 6 MONTHS
2. PROTECTS WORM FROM DESSICATION
3. PREVENTS L3 from EATING, so must LIVE OFF OF ENERGY RESERVES
PRE-PARASITIC portion of STRONGYLE LIFE CYCLE…
range?
where are L1/L2 located & what do they feed on?
how long can development range?
HIGHLY DEPENDENT ON ____ ____
range? = EGG –> L3
L1/L2 located in FECES where they FEED ON BACTERIA/DEBRIS
development to L3 can range from 1 –> MULTIPLE weeks
highly dependent on ENVIRONMENTAL CONDITIONS
ID PARASITE
STRONGYLES
STRONGYLE life cycle stages IN HOST..
restricted to WHAT LOCATION?
how can nematodes AVOID death during SEVERE WINTERS?
ONLY IN GI/ALIMENTARY TRACT
avoid death in winter?
–> CAN ARREST IN ALIMENTARY MUCOSA UNTIL WARMER/ABLE TO DEVELOP & WITHSTAND ENVIRONMENT
HAEMONCHUS spp…
“common name?” & why? (+ WHAT SEX)
what KIND of parasite?
2 species of organism & what animals it affects?
adult worms are located WHERE?
2 clinical signs?
better adapted to WHAT kind of environments?
“BARBER POLE WORM” –> feeds on BLOOD and has STRIPED appearance for FEMALES
GI NEMATODE
2 species?
1. H. CONTORTUS = CERVIDS, RUMINANTS
2. H. PLACEI = CATTLE in SUBTROPICS/SOUTHERN US
ADULT worms in the ABOMASUM
CLINICAL SIGNS?
1. BLOOD LOSS/ANEMIA
2. SUBMANDIBULAR EDEMA
better adapted to WARMER CLIMATES/SEASONS
OSTERTAGIA/TELODORSAGIA…
“common name?”
describe animals affected in each?
present in WHAT kind of climates? how important is it?
adults are found where?
clinical signs in YOUNG CATTLE?
CHARACTERISTIC LESION? & leads to WHAT?
“BROWN STOMACH WORM”
animals affected?
1. OSTERTAGIA = CATTLE
2. TELODORSAGIA = SHEEP/GOATS
IMPORTANT CATTLE PARASITE in COOLER environments
adults are found in ABOMASUM
in YOUNG CATTLE…
–> CHRONIC ABOMASITIS
CHARACTERISTIC LESION?
–> “MOROCCAN LEATHER” = NODULAR APPEARANCE OF GASTRIC GLANDS due to ENCYSTED LARVAE
–> leads to ABOMASAL DYSFUNCTION
LARGE strongyles…
affects WHAT species?
3 examples of organisms? which one is MOST pathogenic?
prevalence?
adults are found in what 2 locations?
what dangerous disease can they cause? what SPECIFIC organism does this? (2)
larval migration locations in other 2 organisms?
affects HORSES
3 examples?
1. S. VULGARIS –> MOST PATHOGENIC
2. S. EDENATUS
3. S. EQUINUS
currently LOW prevalence
adults can be found in CECUM & VENTRAL COLON
dangerous dz?
= in S. VULGARIS!
1. LARVAE can MIGRATE and cause ARTERIAL DAMAGE
2. COLIC
larval migrations in…
1. S. EDENATUS = LIVER, PERITONEAL WALL
2. S. EQUINUS = LIVER, PANCREAS
WHY are large strongyles NOT COMMON/IMPORTANT anymore?
why do we NOT see resistant population of LARGE STRONGYLES?
in the past, owners used to CONSTANTLY ROTATE DIFFERENT DEWORMERS, so it’s mostly gone!
not sure why we don’t see resistance, but IF YOU GIVE IVERMECTIN, KILLS LARGE STRONGYLES WITHOUT DEVELOPMENT OF RESISTANCE
CYATHOSTOMINAE
aka “name?”
commonality?
2 locations adults are found in?
3 seasons the clinical signs tend to occur?
3 clinical signs?
what stage of development is MOSTLY responsible for PATHOLOGY? (2)
aka SMALL STRONGYLES
MOST COMMON PARASITE OF HORSES
adults found in CECUM & COLON
3 seasons?
1. LATE FALL
2. WINTER
3. EARLY SPRING
3 clinical signs?
1. WATERY D+
2. SEVERE INFLAMMATION OF INTESTINE
3. OFTEN FATAL
LARVAL MIGRATION is MOSTLY to blame for pathology!
1. ENCYSTS in MUCOSA OF INTESTINE causing ULCERS
2. produces “PEPPERED” appearance to mucosa
ID PARASITE & LESION
CYATHOSTOMINAE
“PEPPERED” ULCERS ACROSS MUCOSA
ID 2 POTENTIAL DZs?
OSTERTAGIA/TELADORSAGIA
3 concepts of LA parasitology…
- ALL livestock EVOLVED WITH PARASITES, they’re considered “NORMAL FLORA”
- can get INFECTED while GRAZING because they GRAZE WHERE THEY POOP
- infection is NORMAL AND EXPECTED, we can use QUANTITATIVE DIAGNOSTIC TESTS
ASCARIDS…
species in HORSES, RUMINANTS, SWINE?
lives in WHERE? occasionally found in WHAT OTHER 2 LOCATIONS?
females are VERY ___
what’s special about the eggs?
pre-patent period?
species in…
HORSES = PARASCARIS spp.
RUMINANTS = TOXOCARA VITULORUM
SWINE = ACARIS SUUM
lives in the SMALL INTESTINE, but occasionally found…
1. STOMACH
2. CECUM
females are VERY FECUND
eggs can be VERY RESISTANT
PPP = 3-8 weeks
ID PARASITE
ASCARIDS
ASCARID LIFE CYCLE…
what TYPE of life cycle?
what is the INFECTIVE stage?
what growth occurs in ENVIRONMENT?
what growth occurs in the LIVER?
what’s special about L3 stage? (4)
DIRECT life cycle!
INFECTIVE stage = EGG that’s been SHED INTO FECES WITH THIRD-STAGE LARVAE
in ENVIRONMENT = L1 –> L3 WITHIN EGG
in HOST = MIGRATION & GROWTH occurs within the LIVER
L3 stage…
1. can survive up to 6 months in ENVIRONMENT
2. protects worm from DESSICATION
3. DOUBLE CUTICLE
4. UNABLE TO EAT so NEEDS TO LIVE OFF OF ENERGY RESERVES
ASCARIDS…
how QUICKLY can eggs become INFECTIVE? under WHAT conditions?
eggs are covered by WHAT?
can be TRANSMITTED via WHAT kind of host?
does NOT cause what 2 kinds of infections?
where do L3s inside eggs HATCH? (2 locations)
eggs can become infective in 2 WEEKS UNDER FAVORABLE CONDITIONS
eggs are covered with STICKY, PROTEIN COATING
CAN be transmitted by INGESTION via PARATENIC HOST
DOES NOT CAUSE VERTICAL TRANSMISSION, so doesn’t cause these 2 infections…
1. TRANSPLACENTAL
2. TRANSMAMMARY
L3s hatch in…
1. STOMACH
2. SMALL INTESTINE
ID ORGANISM & LESION
what SPECIES of animal is this CHARACTERISTIC in? what sequelae does it cause/when?
“MILK SPOT LESIONS” = ASCARIS SUUM
from ASCARID L3 LARVAE penetrating the GUT WALL and MIGRATING TO THE LIVER
IN PIGS, THIS IS A HALLMARK SIGN because it CAUSES VERMINOUS PNEUMONIA ~7 days POST-INFECTION
what’s the BIGGEST effect of ASCARIDS on LA/why?
ECONOMIC IMPACTS from DECREASED PRODUCTION due to LIVER DYSFUNCTION and INABILITY TO REACH APPROPRIATE WEIGHT
ASCARIS SUUM…
most ___& ___ important disease in pigs…
diagnosis is based on what 2 things?
when do the main pathologic events occur?
CHRONIC infection (2)
ACUTE infection (2)
contagion? (2)
treatment options? (1)
PREVENTION?
COMMON, ECONOMICALLY IMPORTANT
diagnosis..
1. CLINICAL findings
2. NECROPSY findings
MAIN pathologic events occur DURING THE PRE-PATENT PERIOD (BEFORE 2 MONTHS POST-INFECTION)
CHRONIC infection…
1. ADULT worms
2. POOR FEED CONVERSION/ECONOMIC IMPACT
ACUTE infection…
1. LARVAL worms
2. ACUTE RESPIRATORY DZ
contagion?
1. ZOONOTIC!
2. not NECESSARILY pathologic in humans though
treatment options?
1. PYRANTEL = best for when larvae are ACTIVE
prevention?
–> TREAT/CLEAN sows with SOAP and WARM WATER ~2 WEEKS BEFORE FARROWING
PARASCARIS…
in WHAT species?
2 organisms?
most important parasite in ___
what stage/manifestation is the MOST dangerous? 4 c/s associated?
in HORSES
2 organisms…
1. P. EQUORUM
2. P. UNIVALENS
most important parasite in FOALS
ADULT WORMS IN SMALL INTESTINE…
1. GUT MOTILITY
2. INTUSSUSCEPTION
3. IMPACTIONS
4. RUPTURE OF SI
ID PARASITE in SI of FOAL
PARASCARIS
FASCIOLA HEPATICA…
“common name?”
what type of parasite is this?
morphology? (2)
describe eggs (3)
LOCATION?
what are the 6 definitive hosts? (which is most common?)
INTERMEDIATE hosts?
“LIVER FLUKE”
this is a GI TREMATODE
morphology?
1. LARGE, LEAF-SHAPED worm
2. have “SHOULDERS” = CEPHALIC CONE
EGGS…
1. DENSE
2. GOLDEN to DARK-BROWN
3. have OPERCULUM at one end
location = BILE DUCTS
definitive hosts?
1. RUMINANTS MOST COMMON
2. camelids
3. pigs
4. horse
5. rabbit
6. HUMANS (zoonotic)
intermediate hosts? = AQUATIC SNAILS
ID PARASITE
FASCIOLA HEPATICA “liver fluke”
