Exam II Flashcards
Which class of parasites has these 4 main stages of life? Operculated eggs-Miracidia-Sporocyst-Cercariae-Metacercariae-Adults
Trematodes
A dog comes in suffering from an intermittent cough and you find large, oval, yellow, operculated eggs in the feces after performing a fecal sedimentation test. The dog had recently been around lakes/rivers. What parasite could this be?
Paragonimus kellicotti
“Lung fluke”
Which parasite is associated with neorickettsia helminthoeca in dogs and has a very short PPP ( 1 week)?
Nanophyetus salmincola
“Salmon poisoning fluke”
How can nanophyetus salmincola be treated?
Praziquantel for the fluke and tetracycline for the nanophyetus salmincola
Which parasite can cause lizard poisoning with subsequent hepatomegaly and icterus in cats? How do cats become infected?
Platynosomum fastosum
Ingesting an obligate paratenic host (lizard) with infective metacercariae
A dog presents with pulmonary hemorrhaging and you find very large operculate eggs (130um) in the stool after performing a fecal sedimentation test. The owner tells you that they found the dog eating a frog about 5 weeks ago. What parasite could this be? What stage is causing the hemorrhaging?
Alaria spp.
“Intestinal fluke”
Migrating mesocercariae
T/F: Trematodes are very selective in their snail IH selection.
True
Which trematodes that infects dogs/cats has the longest and the shortest PPP?
Platynosomum fastosum has the longest ( 2-3 months)
Nanophyetus salmincola has the shortest ( 1 week)
What are the most common trematodes that have cats and dogs as the final host? Which are zoonotic?
Paragonimus kellicotti (zoonotic) Nanophyetus salmincola (zoonotic) Alaria spp. (zoonotic) Platynosomum fastosum (cats only)
What is the difference between mesocercariae and metacercariae?
Mesocercariae is a stage like metacercariae but only found with Alaria spp.
Which parasite can cause death before patency in sheep and goats? This parasite is spread by white tailed deer, infects the liver, and has metacercariae as the infective stage.
Fascioloides magna
How does fascioloides magna inflict so much damage in sheep and goats, but not in cattle/pigs/horses?
Cattle/pigs and horses are dead end hosts while sheep/goats are aberrant hosts. This means a cyst never forms in the aberrant hosts, causing the metacercariae to migrate through the liver until they cause enough damage to cause death.
What are the best way to treat and prevent a fascioloides magna problem?
Drain and dry pastures to control snail population
Don’t let deer/elk in the same area as livestock
Use flukicides to treat migrating immature flukes
Fasciola hepatica is a major problem for livestock owners throughout the United States. If owners were to treat their livestock, when is the best time to treat adults flukes in the southwest or northwest USA?
Northwest: Spring
Southwest: End of Fall/Before Winter
You go out to a cattle farm to perform a necropsy on a steer. You find that it has pipestem liver and leaf shaped, 3 cm long organisms in the gall bladder. The rancher tells you that the cow was exhibiting diarrhea, bottle jaw, and inappetence before it died. What parasite could this be?
Fasciola Hepatica
“Liver fluke”
This fluke is red, shaped like a pear, and between 5-13 mm in length. It causes disease in large animals before PPP and you can’t see eggs so must rely mostly on clinical signs to diagnose. Which parasite is this, what parts of body does it infect and what clinical signs are you most likely to see?
Paramphistomum spp.
Immature fluke found in duodenum and become adults in the rumen.
Anorexia clostridium infection, bottle jaw, enteritis, diarrhea mostly in young animals
How can you treat paramphistomum spp. at the immature and adult stage?
Oxyclozanide for both stages
Niclosamide for immature stage
Which fluke species in large animals has the largest egg?
Paramphistomum spp. 160 um!!
Which large animal fluke species as the longest prepatent period and which has the shortest?
Paramphistomum spp and F. Hepatic have the shortest (7-12 weeks)
Fascioloides magna has the longest ( 8 months)
T/F: Fascioloides magna and paramphistomum spp. are zoonotic and Fasciola hepatica is not.
False: Fasciola hepatica is zoonotic while fascioloides magna and paramphistomum spp. are not.
Which parasite causes blackhead in turkeys?
Heterakis gallinarum
Tell me about the egg, infective stage, and the location of infection of heterakis spp.
Thick shelled, oval, smaller than ascaridia spp, eggs.
L2 in an egg inside a paratenic earthworm host
Cecum
The “sneaky” trophozoites in H. gallinarum are from _________ ____________ and cause high mortality in __________.
Histomonas meleagridis
young turkeys
A young chicken is brought into the clinic exhibiting anorexia and small intestine obstruction. You perform a mcmaster fecal float and find oval, thick shelled eggs. Which parasite is this?
Ascaridia spp.
“roundworms”
This parasite is huge and infects the kidney parenchyma of dogs and foxes. They can get it from eating a paratenic or intermediate host ( fish, frog, or earthworm) and it is usually asymptomatic. It is zoonotic. What is it?
Dioctyophyme renale
Name the four types of threadworms we are most concerned with and their host.
Strongyloides stercoralis: Dogs/cats
Strongyloides westerni: Equine
Strongyloides papillosus: Ruminants
Strongyloides ransomi: Swine
What are two very unique things threadworms can be characterized by?
1/3 of their body is composed of the esophogus
Males and females can be free-living
What are two very unique things threadworms can be characterized by?
1/3 of their body is composed of the esophagus
Males and females can be free-living
A piglet dies soon after giving birth. You do a fecal exam on the sow and find eggs containing larvae. The piglet seemed to have been suffering from dehydration and weight loss prior to death, but no eggs were found in the feces. What parasite do you suspect could cause this and why?
Strongyloides ransomi
Very short prepatent period prevents eggs from being seen because piglet dies too quickly.
The sow has immunity to the parasite but was able to pass eggs to it’s offspring via the transmammary pathway.
What does homogonic mean?
Only the adult female parasite enters the host and parasitizes it.
What is the best treatment for Strongyloides spp.?
MCLs
This parasite has an L3 infective stage, infects ruminants, allows adults to develop later immunity towards it, and the adult has 1/3 of the lenght of body as an esophogus. Name this parasite?
Strongyloides papillosus
Which strongyloides spp. can be diagnosed with just an L1 in feces, with no egg? What is the final host for this parasite?
Strongyloides stercoralis
Dogs/cats
Where is the main site of infections of strongyloides spp. adults? What body parts does the L3 have to travel through before they get to the main site?
Small intestine
Mouth or skin to the lungs
T/F: Strongyloides westerni is zoonotic and infects horses.
False: S. Westerni does infect horses, but it is not zoonotic. S. stercoralis is zoonotic and infects dogs/cats.
T/F: Strongyloides westerni is zoonotic, infects horses, and involved prenatal transmission.
False: S. westerni does infect horses, but it is not zoonotic and involved with prenatal transmission. S. stercoralis is zoonotic and involved prenatal transmission.
This parasite has a thin anterior filamentous end is uses to burrow into the subepithelium cecum/colon of it’s host. It has resilient, thick shelled eggs shaped like a footballs that can be identified via fecal floatation. What is it?
Trichuris spp.
Which species of trichuris is rare in cats, but infects dogs and other mammals, is zoonotic, and has an L1 in a egg as the infective stage.
Trichuris vulpis
A dog comes into the clinic and you diagnose it with Trichuris vulpis. What were the clinical signs the dog was most likely exhibiting, how did you diagnose it, and what will you tell the owner in order to prevent reinfection?
If it was mild, dog was most likely asymptomatic. Heavy infection leads can lead to diphtheritic inflammation of cecal mucosa involving diarrhea and weight loss.
It was diagnosed using a fecal float to look for thick shelled , lemon shaped eggs, sometimes with the infective L1 larvae inside.
Tell the owners to immediately pick up feces as the eggs can live for many years in the environment.
Capillaria obsignata infects __________ and causes high _________. The capillaria spp. is very _________ specific and is part of the superfamily _____________.
pigeons
mortality
host
trichinelloidea
What makes capillaria spp. different from the other parasites in the trichinelloidea superfamily ( Trichuris spp, and Trichinella spp.) ?
It can have an indirect life cycle involving earthworms and adult nematodes are found in the alimentary ( birds), respiratory, hepatic, and urinary tracts of hosts.