GI Parasites Flashcards
flagellate protozoa
giardia
tritrichomonas
coccidia protozoa
cryptosporidium
eimeria
cystoisospora
nematodes - ascarids
ascaris suum
parascaris equorum
toxocara cati/cani
toxascaris leonina
toxocara vitulorum
nematodes - strongyles
hookworms
trichuris (whipworms)
cyathostomes (small strongyles)
large strongyles
trichostrongylus (ostertagia, haemonchus, nematodirus)
trematodes
fasciola hepatica
nanophyetus salmincola
cestodes
dipylidium caninum
taenia
giardia
infects young > adult
highly zoonotic
transmission: cyst ingestion
“smiley face” trophozoites
diagnostics: fecal float, PCR/DFA
tritrichomonas
cats only
not zoonotic
transmission: trophozoite ingestion
NO cyst stage - doesn’t survive long in environment
diagnostics: PCR > culture > direct smear
cryptosporidium
many species; young ruminants mostly
HIGHLY zoonotic
transmission: oocyst ingestion
oocysts are IMMEDIATELY infective
causes cryptosporidiosis
diagnostics: fecal float
eimeria
infects young > adult
livestock
NOT zoonotic - species specific
transmission: ingestion of sporulated oocyst
oocysts sporulate in environment
causes coccidiosis
diagnostic stage: unsporulated oocyst
infective stage: sporulated oocyst (4 x 2)
cystoisospora
infects young > adult
dogs, cats, pigs
NOT zoonotic - species specific
transmission: ingestion of sporulated oocyst OR paratenic host
diagnostic stage: unsporulated oocyst
infective stage: sporulated oocyst (2 x 4)
ascaris suum
pigs
weakly zoonotic
transmission: fecal-oral
- liver-lung migration
diagnostics: fecal
diagnostic stage: eggs
infective stage: L3
parascaris equorum
young horses
transmission: fecal-oral
“summer cold” - respiratory + GI signs
toxocara cati/canis
cats (cati), young dogs (canis)
not zoonotic - aberrant hosts get VLM/OLM
transmission (cati): egg or paratenic host ingestion, +/- transmammary
transmission (cani): transmammary, transplacental, egg or paratenic host ingestion
toxascaris leonina
dogs, cats
no transplacental transmission
no liver-lung migration
toxocara vitulorum
ruminants
transmission: fecal-oral
causes intestinal impactions
hookworms (ancylostoma, uncinaria, necator)
infects young > adults
dogs, cats
HIGHLY zoonotic
transmission: ingestion of larvae
- encysts in tissues –> released when sick/stressed
- HEMATOPHAGOUS (anemia, emaciation)
diagnostics: fecal - only active NOT encysted eggs
trichuris (whipworms)
infects adults
dogs, cats, pigs, ruminants, camelids
transmission: ingestion
- prepatent period = 3 MONTHS
diagnostics: fecal - football shaped egg
cyathostomes (small strongyles)
MOST IMPORTANT IN HORSES
horses
transmission: ingestion of embryonated eggs
- must develop ON PASTURE
- HYPOBIOSIS - arrest and release under good conditions
diagnostics: fecal - larvae
large strongyles
MOST IMPORTNAT IN HORSES
horses
transmission: ingestion of embryonated eggs
- must develop ON PASTURE
- cause cranial mesenteric artery thrombosis
diagnostics: fecal - larvae
trichostrongylus - ostertagia ostertagi
MOST IMPORTANT IN CATTLE
young ruminants
transmission: ingestion of embryonated eggs
- targets: gastric glands in abomasum
- must develop ON PASTURE
- HYPOBIOSIS
- prepatent period: 3 WEEKS
type 1: diarrhea
type 2: presents in 2nd grazing season from hypobiosis
trichostrongylus - haemonchus contortus
MOST IMPORTANT IN SMALL RUMINANTS & CAMELIDS
young ruminants
transmission: ingestion of embryonated eggs
- targets: abomasum
- must develop ON PASTURE
HEMATOPHAGOUS
NO DIARRHEA
trichostrongylus - nematodirus
young sheep
survives the cold/winter
highly pathogenic among sheep
fasciola hepatica
sheep and cattle
- sheep: infected by young flukes
- cattle: infected by adult flukes
weakly zoonotic
transmission: requires SNAILS as IH
- prepatent period: 3 MONTHS
diagnostics: fecal/bile sedimentation
liver flukes –> liver failure/cholangiohepatitis
nanophyetus salmincola
dogs
transmission: requires SNAILS and FISH as IH
- ingestion of Neorickettsia infected fluke or salmon/trout
diagnostics: fecal sedimentation
salmon poisoning disease
dipylidium caninum
dogs, cats
HIGHLY zoonotic
transmission: requires FLEAS as IH
- subclinical/pruritis
diagnostics: observation when passing in feces; fecal - egg packets
taenia
dogs, cats, ruminants
transmission: prey on infected animals/carcasses; ingestion in environment
- subclinical/pruritis
diagnostics: fecal - egg packets
