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