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162 Cards in this Set
- Front
- Back
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What is the common name for
Phylum Platyhelminthes? |
Flatworms |
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TRUE or FALSE?
Most flatworms are parasitic? |
TRUE |
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What kind of shape do most flatworms have, and which worms are the exception? |
leaf-shaped or oval
tapeworms (long & thin) |
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TRUE or FALSE:
Flatworms are usually very small. |
FALSE:
Flatworms vary widely in size, from being microscopic to over 200 cm long. |
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TRUE or FALSE:
Many flatworms are hermaphroditic. |
TRUE |
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Name the 3 classes of Platyhelminthes along with their common names: |
1. Cestoda: tapeworms
2. Trematoda: flukes
3. Turbellaria: planarians |
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Which class of flatworms is mostly free-living and carnivorous? |
Planarians |
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TRUE or FALSE:
Planarians are important veterinary parasites. |
FALSE
Planarians are not pathogenic |
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TRUE or FALSE:
Cestodes are all parasitic. |
TRUE |
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What do Cestodes almost always require? |
An intermediate host |
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Adult Cestodes are parasites of the _____________ of ___________________. |
intestines
vertebrates |
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Cestodes - many are important parasites of _________________ animals. |
domestic |
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Cestodes live in the ________________ and are only seen when they are ___________________________________________. |
intestines
passed out with the feces |
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Cestodes are hermaphroditic and ____________ - _____________________. |
self-fertilizing |
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TRUE or FALSE:
Cestodes can infect almost any mammal. |
TRUE |
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What are the 3 parts of the Cestode anatomy? |
1. Scolex (head)
2. Neck
3. Strobila (body) |
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In Cestodes, the strobila consists of a linear series of sets of __________________ ______________ of _____________ ________________. |
reproductive organs
both sexes |
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Each section of the Cestode's strobila is called a ___________________. |
proglottid |
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One tapeworm may contain up to how many proglottids? |
2,000 |
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Why are tapeworms flat? |
So that they can increase their surface area-to-absorption ratio...
They absorb all of their nutrients (no mouth parts) |
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Each tapeworm proglottid is _____________ - _______________ and produces ______________. |
self-fertilizing
eggs |
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New proglottids are produced at the ___________________ end of the tapeworm. |
anterior |
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Proglottids _______________ reproduce and produce _____________ as they travel towards the _________________ end of the organism. (Strobilation.) |
sexually
eggs
posterior |
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What is the state of containing fully developed eggs? |
gravid |
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What happens when a gravid proglottid reaches the end of the strobilus? |
It breaks off and is excreted in the feces. |
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What is the scolex equipped with and what does this allow them to do? |
holdfast organs
maintain the position of the parasite in the host's gut...
allows them to hold onto / penetrate the host intestine |
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What is the structure called that contains the hooks or other attachment appendages of the scolex? |
rostellum |
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What kind / how many hosts does a tapeworm require? |
Definitive Host - 1
Intermediate Host - 1 or 2 |
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Intermediate hosts of the tapeworm may be _________________ or __________________. |
Vertebrates
Invertabrates |
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Give some examples of Intermediate Hosts (both types) for Cestodes: |
mice rabbits
crustaceans insects mollusks mites annelids |
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Cestodes of the greatest veterinary importance have ______________ intermediate host(s)?
(how many) |
ONE |
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If the tapeworm's Intermediate Host is a mammal, the Genus is: |
Taenia spp. |
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If the tapeworm's Intermediate Host is a an arthropod, the Genus is: |
Dipylidium spp. |
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TRUE or FALSE?
Life cycles of Cestodes vary widely and many are not well known. |
TRUE |
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Where are sexually mature tapeworms found in the definitive host? |
intestines |
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TRUE or FALSE?
Mature adult tapeworms don't typically live very long - normally a few days to a few weeks. |
FALSE -
they can live from a few days to many years
(depending on the species) |
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Mature adult tapeworms may produce from ______________ to _________________ of eggs. |
a few
millions |
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TRUE or FALSE:
Each proglottid has 1 - 2 sets of male and female reproductive organs. |
TRUE |
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After eggs and/or proglottids are excreted in feces, they are __________________ by intermediate host. |
ingested |
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Where do Cestode eggs hatch? |
Inside the Intermediate Host, in a parenteral site. |
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Larvae in the parenteral site of the intermediate host develop into a _______________________. |
cysticercus |
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A cysticercus is also known as a _______________. |
metacestode |
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Cysticercus & Metacestode both refer to what stage of development of the tapeworm? |
Juvenile |
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How does the juvenile cysticercus (tapeworm) get into the body of the Definitive Host? |
Definitive host ingests Intermediate host |
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In the definitive host, where do the tapeworm larvae go? |
small intestine |
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What happens to the cysticercus when it arrives in the small intestine of the definitive host? |
Most of its body is digested - only the scolex and neck remain. |
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The ____________ attaches to the inside of Definitive Host intestines. (Cestoda) |
scolex |
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TRUE or FALSE:
Adult cestodes in intestines of cats and dogs cause serious disease. |
False - they rarely cause serious disease. |
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What symptoms might you see in a cat or dog with a tapeworm? |
unthrifty malaise irritability colic mild diarrhea
*pruritis ani in dogs |
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What symptoms would you see in severe cases of tapeworm infection? |
emaciation
seizure |
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Tapeworms - Genera of veterinary importance
(name 4) |
1. Taenia
2. Diphyllobothium
3. Echinococcus
4. Spirometra |
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How would you diagnose a tapeworm infection?
(list 2 ways) |
find eggs or proglottids in feces via:
1. direct smear
2. flotation
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Tapeworm eggs may be confused with eggs from what other worm? |
Hookworm |
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What are the 2 varieties of tapeworms we study? |
1. Dipylidium caninum
2. Taenia pisiformis |
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Which worm (genus + species) is commonly known as the "cucumber tapeworm" or the "rice grain" tapeworm? |
Dipylidium caninum |
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TRUE or FALSE:
Dipylidium caninum is common in cats. |
FALSE |
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TRUE or FALSE:
Dipylidium caninum is the most common tapeworm of dogs.
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TRUE |
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TRUE or FALSE:
Dipylidium caninum infection is very rare in humans. |
TRUE |
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How might you know your dog has Dipylidium caninum? |
You'll see the proglottids in the feces or coming out the butt. (they may be moving) |
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Egg packets of Dipylidium caninum contain about how many eggs? |
about a dozen |
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How many suckers does the adult Dipylidium caninum have on its scolex? |
four |
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How long can Dipylidium caninum get? |
up to 50 cm long
(about 20 inches) |
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Dipylidium caninum - is the life cycle direct or indirect? |
Indirect |
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Who are the intermediate hosts of Dipylidium caninum? |
usually fleas
sometimes lice |
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Predilection site of Dipylidium caninum: |
small intestine |
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Prepatent Period of Dipylidium caninum: |
2 - 3 weeks |
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How does the flea or louse get Dipylidium caninum? |
Perianal region of infected dog becomes contaminated with eggs from feces.
Larval flea / louse ingests the eggs
(Dog ingests infected flea while grooming)
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Are eggs of Dipylidium caninum shed in packets? |
YES |
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What develops in the intermediate host and becomes infective? (usually occurs in the MUSCLE of the intermediate host) |
cysticercus |
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TRUE or FALSE:
Dipylidium caninum eggs are not infective to vertebrates - only to fleas and lice. |
TRUE |
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Treating fleas: you must treat not only the animal, but also the ____________________. |
House (environment) |
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TRUE or FALSE:
Zoonosis: Dipylidium caninum infection rarely occurs in humans. When it does, it's usually always in children. |
TRUE |
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Who are the definitive hosts of Taenia pisiformis? |
dogs foxes other canids |
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What animal is the Intermediate Host of Taenia pisiformis? |
Rabbits & Hares |
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Taenia pisiformis infection is particularly common in:
A. urban indoor dogs B. farm and rural dogs |
B - farm and rural dogs
(more likely to eat rabbits) |
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Predeliction site of Taenia pisiformis: |
small intestine |
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Prepatent period of Taenia pisiformis: |
1 - 2 months |
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Are Taenia pisiformis eggs shed in packets? |
NO - single eggs are seen in feces. |
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What is a physical characteristic of Taenia pisiformis eggs? |
thick, striated shells |
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How does the rabbit (intermediate host) get infected with Taenia pisiformis? |
Proglottids are passed in feces then crawl from feces onto surrounding vegetation.
Eggs are released from proglottid into environment.
Rabbit ingests eggs while eating vegetation. |
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Taenia pisiformis eggs hatch in the ________________________ of the rabbit and then migrate to the ______________. |
small intestine
liver |
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Eggs develop into the ____________________ (infective stage) in the rabbit, forming a dormant cyst. |
cysticercus (metacestode) |
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After the dog eats the rabbit, the cysticercus attaches to the dog's _________________________ and matures there. |
small intestine |
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Symptoms of Taenia pisiformis: |
usually asymptomatic
(very heavy infections - intestinal blockage) |
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Diagnosing Taenia pisiformis: |
proglottids or eggs in feces |
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How can you tell Taenia pisiformis proglottids apart from Dipylidium caninum proglottids? |
Taenia pisiformis proglottids are much larger and more rectangular. |
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Taenia taeniaeformis - what animal is the definitive host? |
the cat |
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Can dogs get Taenia taeniaeformis? |
rarely |
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Taenia taeniaeformis - who is the intermediate host? |
rodents |
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Best method of preventing tapeworms: |
Flea control |
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Trematodes are commonly called ___________. |
Flukes |
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What are the 3 Orders within Class Trematoda? |
Monogenea
Aspidogastrea
Digenea |
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Which of the 3 Orders within Class Trematoda causes veterinary diseases? |
Digenea |
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Order Digenean: fluke undergoes ___________________ development. |
indirect |
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What hatches from the Digenean fluke is different in ___________ _____________ from the adult form. |
body form |
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Digenean flukes develop with _________________. |
metaphorphosis |
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TRUE or FALSE:
Digenean flukes are hermaphroditic. |
TRUE |
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How many hosts to Digenean flukes require? |
at least two |
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Digenean flukes have complicated life cycles.
Sexual and asexual generations parasitize ____________________ hosts. |
alternate |
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What animal is usually the first host of a Digenean fluke? |
mollusk or annelid |
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The second host of a Digenean fluke is: |
can be almost any mammal. |
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Anatomy of Order Digenean:
Most are _______________ and ________ - shaped. |
flattened
oval |
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Flukes have a powerful ________ _____________ that surrounds the mouth. |
oral sucker |
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TRUE or FALSE:
Flukes are not self-fertilizing. |
FALSE - many of them are self-fertilizing |
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Name two of the major parasitic flukes from the order Digenean: |
1. Fasciola hepatica
2. Paragonimus kellicotti |
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What is the common name for Fasciola hepatica? |
liver fluke |
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What animals are infected by Fasciola hepatica? |
ruminants
(mainly cows) |
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Predilection site of Fasciola hepatica: |
bile duct |
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Fasciola hepatic are _____________ - shaped. |
Leaf |
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TRUE or FALSE:
Fasciola hepatica are hermaphroditic. |
TRUE |
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The adult body of Fasciola hepatica is a "little bag" of _____________________________________. |
male & female reproductive organs |
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Fasciola hepatica have two types of suckers: |
oral & ventral |
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Life cycle - where do the adult liver flukes of cows live? |
in the bile duct |
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Liver fluke eggs produced by the adult go through the __________________ and are _________________________. |
intestines
excreted in feces |
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Where do the liver fluke eggs hatch? |
in the environment |
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What comes out of the liver fluke egg? (the name of the juvenile form) |
a ciliated miracidium |
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How long after excretion will the liver fluke eggs hatch? |
2 - 4 weeks |
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How does the liver fluke miracidium infect the 1st Intermediate Host? |
it penetrates the skin (it's usually a snail.) |
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If the liver fluke miracidium doesn't find a host within 24 hours, what happens? |
it will die |
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What happens to the liver fluke miracidium inside the snail? |
It discards its ciliated "skin" and metamorphises into a simple form called a sporocyst. |
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What is the juvenile form of the liver fluke that eventually comes out of the snail called? |
cercaria |
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When the cercaria leaves the snail, where does it go? |
Into the water (it has a tail and can swim) |
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Once in the water after leaving the snail, what does the liver fluke cercaria do? (4 things) |
1. attaches to an aquatic plant
2. loses its tail
3. encysts
4. metamorphosises into a metacercaria |
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What are the 4 juvenile stages of the liver fluke and where are they found? |
1. miracidium (what comes out of egg)
2. sporocyst (becomes this IN SNAIL)
3. cercaria (comes OUT of snail)
4. metacercaria (form on aquatic vegetation) |
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Which juvenile form of the liver fluke is the infective stage? |
metacercaria |
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TRUE or FALSE:
Metacercaria (liver fluke) are not very resistant. |
FALSE - they may survive on HAY for a long time. |
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If ingested by a ruminant, the metacercaria becomes a young fluke and invades the mammalian host's _______________. |
liver |
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The metacercaria (liver flukes) develop into adults and produce eggs in the ruminant's ______________________. |
bile duct |
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How long does the complete life cycle take for Fasciola hepatica, and in what season does it normally happen? |
3 - 4 months
Summer |
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Prepatent period for Fasciola hepatica: |
8 - 10 weeks
(time between when mammal ingests metacercaria and when eggs are produced in bile ducts) |
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Symptoms of liver fluke infection: |
severe liver inflammation abdominal pain disinclination to move |
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TRUE or FALSE:
Acute Liver fluke infections are not usually fatal. |
False - they are highly fatal |
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TRUE or FALSE:
Some cows may not display any symptoms prior to death from acute liver fluke infection. |
TRUE |
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Death from Fasciola hepatica infection is usually due to _____________ ____________ from a ____________________ liver. |
blood loss
hemorrhaged |
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TRUE or FALSE:
Chronic Fasciola hepatica is never fatal. |
FALSE - chronic liver fluke infection CAN be fatal |
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TRUE or FALSE:
Acute fluke disease is more common than chronic fluke disease. |
FALSE - chronic fluke disease is much more common. |
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What are some symptoms you might see in a chronic liver fluke infection? |
overal weakness weight loss anemia chronic diarrhea swelling in abdomen obstructed bile duct destruction of liver tissue hepatic scarring |
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What happens if one fluke is found in a slaughter house animal? |
condemnation |
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Diagnosis of Fasciola hepatica:
(4 ways) |
1. find adult flukes upon necropsy (in liver or bile ducts)
2. find eggs in feces upon necropsy
3. sucrose fecal float (eggs may be distorted)
4. sedimentation test (preferred) |
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TRUE or FALSE:
Fasciola hepatica eggs are difficult to identify. |
FALSE |
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Fasciola hepatica eggs are OVAL with a visible ______________ (lid). |
operculum |
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What is the best test method to use when diagnosing Fasciola hepatica? |
sedimentation technique |
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Name 3 common liver fluke pathogens: |
1. Fasciola hepatica
2. Fasciola gigantica
3. Fasciola magna |
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TRUE or FALSE:
Fasciola gigantica and Fasciola magna are larger and more common than Fasciola hepatica. |
FALSE - they are larger, but they are not as common. |
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What is the scientific name of the lung fluke? |
Paragonimus kellicotti |
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Paragonimus kellicotti is usually found in __________ in the lungs. |
cysts |
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Which animal is the main animal affected by Paragonimus kellicotti? |
cats
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What other species can be infected by lung flukes? |
dogs humans
(and other wild / domestic animals) |
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What color are adult lung flukes? |
reddish-brown |
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How big are adult lung flukes? |
about a 1/2 inch |
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TRUE or FALSE:
Paragonimus kellicotti eggs have a visible operculum. |
TRUE |
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What color are the eggs of Paragonimus kellicotti? |
golden brown
(look like a jewel) |
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What happens to the Paragonimus kellicotti eggs once they leave the lungs? |
They are coughed up, swallowed, and excreted in feces. |
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The life cycle of Paragonimus kellicotti is:
A. Direct
B. Indirect |
B - Indirect |
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How many hosts does Paragonimus kellicotti require? |
at least two |
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What animals are the 1st intermediate host of lung flukes? |
snails |
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What animals are the 2nd intermediate host of lung flukes? |
Crayfish |
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The life cycle of Paragonimus kellicotti is similar to what other worm? |
Fasciola hepatica
(liver fluke) |
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What are some symptoms of lung fluke infection? |
chronic, deep, intermittent cough
weak, lethargic
(may be asymptomatic) |
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How to diagnose liver fluke infection: |
1. eggs in feces or sputum
2. sedimentation test
3. fecal flotation |
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If using a fecal float to identify liver fluke eggs, what must be used? |
high density sucrose |
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What feature helps to identify the eggs of Paragonimus kellicotti? |
the operculum |
