Exam II Flashcards by Raquel Schenone

Which class of parasites has these 4 main stages of life? Operculated eggs-Miracidia-Sporocyst-Cercariae-Metacercariae-Adults

Trematodes

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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”

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Which parasite is associated with neorickettsia helminthoeca in dogs and has a very short PPP ( 1 week)?

Nanophyetus salmincola

“Salmon poisoning fluke”

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How can nanophyetus salmincola be treated?

Praziquantel for the fluke and tetracycline for the nanophyetus salmincola

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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

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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

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T/F: Trematodes are very selective in their snail IH selection.

True

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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)

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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)

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What is the difference between mesocercariae and metacercariae?

Mesocercariae is a stage like metacercariae but only found with Alaria spp.

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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

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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.

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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

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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

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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”

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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

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How can you treat paramphistomum spp. at the immature and adult stage?

Oxyclozanide for both stages

Niclosamide for immature stage

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Which fluke species in large animals has the largest egg?

Paramphistomum spp. 160 um!!

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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)

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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.

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Which parasite causes blackhead in turkeys?

Heterakis gallinarum

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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

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The “sneaky” trophozoites in H. gallinarum are from _________ ____________ and cause high mortality in __________.

Histomonas meleagridis

young turkeys

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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”

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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.

A cat presents in the clinic with hair like parasites in the urinary tract, and barrel shaped thick shelled eggs in feces, but no obvious clinical signs. What is this parasite and why is it important to manage?

Capillaria spp. | It is zoonotic and is usually an incidental finding.

This parasite infects the cecum/colon of swine, provokes a strong immune reaction the results in the expelling of the worms, is zoonotic, and has a adult stage that looks like a whip.

Trichuris suis

Humans are the only host that exhibit clinical signs with this parasite. L1 is the infective stage and develops into an adults in the small intestine. It can be diagnosed by finding it coiled in striated muscle in pigs and other mammals. Humans become infected by eating undercooked meat. What is it?

Trichinella spp.

What are the ways in which we can prevent animals from becoming infected with Trichinella spp.?

Reducing tail biting and rats in piggeries, not feeding animals raw meat.

Which parasite has a dung beetle as an intermediate host, can cause large granulomas in the esophagus/stomach in final host ( dogs) that can lead to osteosarcomas, spondylosis, or regurgitation/trouble swallowing?

Spirocerca lupi

The infective stage of spirocerca lupi is ______ and the diagnostic stage is _______ encysted in a IH or PH. If no eggs can be found, there likely is no _______ present on the granuloma/nodule.

L3 L1 fistula

Spirocerca lupi adults are _______ in color, ______ in length with _______ looking eggs that contain a ______ with a ______ shell.

``` red-pink up to 8 cm. paperclip L1 thick ```

What is the common name and prepatent period for S. lupi?

Esophageal worm | 6 months

This parasite is very similar to Spirocerca lupi, but it infects cats in addition to dogs, the adults reside in the stomach, the IH are beetles, cockroach and crickets, and it causes vomiting, hemorrhaging, catarrhal gastritis and blood in the feces. What is it?

Physaloptera spp.

What is different about the adult Physaloptera spp. when compared to S. Lupi in regards to the way it attaches to the mucosa of the site of infection?

Physaloptera spp. adults have forceps that latch onto the the mucus instead of forming nodules.

_________ and _________ can infect all equids and have the _______ and ______ flies as intermediate hosts passing L3 larvae into the hosts oral cavity. The adults reside in the stomach and the larvae are very aggressive. MCLs and fly control are the best treatments.

Habronema spp. Draschia Megastoma Musca spp. Stomoxys calcitrans

Habronema spp. can cause ________ __________ which are the consequence of L3 being deposited on the skin instead of the mouth.

Summer sores

What types of problems can drashia megastoma cause in horses?

Usually, light infections with adults are non-pathogenic, but sometimes, they can cause gastritis when nodules are formed close to the margo plicatus creating tumors.

Why is it so hard to diagnose Habronema spp. and Draschia megastoma? What is the best way to diagnose?

The eggs are small and thin shelled making them hard to see..they do not float well. Clinical signs and larvae skin scraping to look for L3s

Which parasite infects horses, has adults that live in the colon that migrates through the anus to lay eggs around the perineum, and has an L3 infective per os stage?

Oxyuris equi

What can lead to pruritus in a horse during an infection of oxyuris equi?

A gelatinous substance left with the eggs on the perineum.

Will you find Oxyuris equi eggs in the feces of horses? How would you diagnose this parasite?

No, must use adhesive tape method or perianal scraping to see eggs.

If a client came in worried that their children would get pinworms from the dog/cat, what would you tell them?

That is not possible because the different species of pinworms are species specific. The only species that can infect humans is enterobius vermicularis.

What determines the severity of canine heartworm disease?

Determined by pulmonary blood flow; if a dog exercises, this increases the severity of clinical disease.

Cats become infected with Dirofilaria immitis. Which organs have the greatest pathology?

Lungs

What kind of vectors do the members of the superfamily filarioidea utilize?

Mosquitoes, fleas, ticks, lice, mosquitoes, and culicoides spp.

Dogs can easily tolerate more than 30 adult heartworms before clinical disease is evident. What level can a cat tolerate?

No more than 6, only 1-2 are commonly present.

Heartworm monthly preventatives are used to treat which life stages of D. Immitis? What are these? Do we want to just kill some stages or all stages?

L3 and early L4 ( not older than one month) MCLs like Ivermectin, Milbemycin, selamectin, and Moxidectin DEC: a daily oral for dogs that are mff free ALL

Why is it important to give a dog doxycycline in addition to MCL's when treating heartworms?

D. immitis harbors the intracellular bacteria Wolbachia spp. which may contribute to the pathogenesis of the disease.

At what age can you start giving a dog monthly heartworm preventatives?

6-8 weeks

What is the PPP for D. immitis?

6-9 months

What parasite has mff that look similar to D. immitis and must be differentiate with a blood smear and/or antigen test? How would you differentiate it?

Acanthocheilonema reconditum | It has a buttonhook/curved tail while D. immitis is straight

What is the site of infection for acanthocheilonema reconditum?

Adults in the subcutis with mff in the blood

Which parasite part of the Filaroides subfamily infects horses, can be found tightly coiled in tissue nodules especially in the nuchal ligament, and can result in pruritic dermatitis?

Onchocerca cervicalis

What D. immitis stage does the antigen test detect and how many adults must usually be present?

Sexually mature females | Three or more

In the __________ order of cestodes, the adults have a scolex and ________ with the use of _______ IH. In the pseudophyllidea order of cestodes, the adults have a scolex and ________ with the use of ______ IH's. The oncosphere in the former does not have __________, while the oncosphere in the latter does.

``` Cyclophyllidea Suckers one bothria two cilia ```

Which cestode has a evaginated cysticercus and uses two intermediate hosts ( Ctenocephalides spp. and trichodectes canis) to infect dogs/cats?

Dipylidium caninum

What is the prepatent period for D. caninum?

21 days

What are the two main cestodes of fowl?

Choanotaenia spp. and Raillietina spp.

Which parasite can have triangular or trapezoid shaped eggs, have the greatest effect on young lambs/kids, can be treated with praziquantel/albendazole, and may overshadow the cause of other diseases?

Moniezia spp.

Which cestode can lead intussusception of the terminal ileum and cecum in horses after they ingest a oribatid mite containing the cysticercoids?

Anoplocephala Perfoliata

Nodular tapeworm disease is caused by which parasite? What are the clinical signs in the final host?

Raillietina spp. | In fowl it can cause reduced growth, emaciation and weakness.

Which cestode in horses is larger, but less pathogenic than anoplocephala perfoliata?

Anoplocephala magna

Which parasites have a hexacanth embryo?

``` D. caninum Raillietina spp./Choanotaenia spp. Anoplocephala spp. Moniezia spp. Taenia spp. Echinococcus spp. ```

This parasite infects cats, has a strobilocercus larval stage that infects a rodent intermediate host to eventually mature in the liver of the final host. What is it?

Taenia taeniaeformis

Do Taenia spp. have a cysticercoid or a cysticercus larval stage?

Cysticercus ( invaginated) with T. Taeniaeformis having a strobilocercus.

What is the prepatent period for T. saginata and T. solium?

T Saginata: 70-85 days | T. Solium: 35-85 days

Which adult cestode can get the biggest, T. crassiceps or T. taeniaeformis? Sizes?

T. taeniaeformis can not get bigger than 70 cm while T. crassipes can not get bigger than 17 cm.

In which Taenia spp. can a human act as an intermediate host? What about as a final host?

IH: T. crassiceps and T. solium FH: T. saginata and T. solium

This parasite has endogenous hydatid cysts as the larval stage that reside in the liver and lungs, is zoonotic, has a PPP of 6 weeks, and usually involves an herbivore intermediate host.

Echinococcus granulosus

Can you tell the difference between Taenia spp. and Echinococcus granulosus/multilocularis eggs? What do they look like?

No! | Thick shells, round, and small.

Which parasite can be fatal in humans, has exogenous hydatid cysts as the larval stage residing in the liver, and can metastasize to other organs, and can cause echinococcosis in dogs?

Echinococcus multilocularis

Diphyllobothrium latum eggs were detected in the feces of a certain host in your clinic. This host has macrocytic anemia. How did this host become infected with this parasite and which host is it?

Dog | Ate a freshwater fish containing a plerocercoid that had ingested a copepod infected with procercoid.

A ciliated oncosphere is called a ___________ in the __________ order of cestodes.

Coracidium | Pseudophyllidean

What is the scientific name for the zipper worm and what type of parasite is this?

It is a pseudophyllidean cestode and its name is Spirometra spp.

How many intermediate hosts does spirometra have and what disease can this parasite cause in humans?

Two IH hosts...a crustacean and then a fish/bird/rodent or human. It can cause sparganosis, but will not be infected with the adult.

How would you diagnose spirometra spp.?

Eggs in feces, make sure to differentiate from trematode eggs.

Which two species of insects would you not want to treat compost for (the spot where they lay their eggs)?

Stomoxys calcitrans | Musca autumnalis

What is the common name and host of Haematobia irratans?

Horn Fly | Cattle

The layinng of eggs by the fly on the host is called the________ while the damage they cause is called the __________.

blow | strike

If an animal has become infested with fly maggots (larvae), we call this __________.

Myiasis

If there are more than 200 of these types of insects on one cattle host, it can cause economic loss. Which parasite?

Haematobia irritans

This insect is very small, has a short piercing proboscis and the females are the only ones that take blood meals. It can transmit Onchocerca cervicalis.

Culicoides spp,

Which species blood sucking diptera are the hardest to control?

Tabanus spp. | Chrysops spp.

What is the life cycle of Diptera?

Egg Larva Pupa Adult

The life cycle E-N-N-N-A is characteristic of which insect order?

Phthiraptera: Lice

Which insect infects the stomach of horses with third stage instars?

Gasterophilus spp. | "Bot Fly

Which cestodes have a cysticercus larval stage?

All of the Taenia spp. except Taenia taeniaeformis