Parasitology Lecture Midterm Flashcards
____________ may cause fatal pneumonia in puppies if mom was infected
Roundworm/Toxocara
why would we use a tapeworm crush?
to examine eggs within the segment of a tapeworm that does not otherwise expel its eggs
what are 3 possible paratenic hosts of Toxocara?
rodents, rabbits and earthworms
Are hookworms zoonotic?
Yes; via cutaneous larval migration
are hookworms bloodfeeders?
yes
what two factors decide the clinical signs of Toxocara infection?
number of worms & age of host
The prepatent period of Dioctophyma is _______ months
3-6
why is Toxocara a public health concern?
because our common household disinfectants do not kill toxocara eggs
What is the life cycle of Strongyloides?
L3 is infective and ingested or penetrates the skin - migrates through blood - lungs and trachea, coughed up and swallowed - adult female resides in small intestine - deposit eggs and L1 is passed in feces
What paratenic host does Pearsonema plica use?
earthworm
what are cestodes?
flatworms that are ribbon-like and segmented into Proglottids behind a Scolex
How big do Heartworms get?
up to 30 cm
how is Toxascaris transmitted?
ingestion of egg
why is single sex infection of Toxocara a concern?
infertile worms make diagnosis by fecal float impossible
What are some clinical signs of Whipworm infection?
Sometimes one, damage of tissue as blood vessels in severe cases. Can also show severe diarrhea, dehydration, emaciation and death
What is an intermediate or secondary host?
host in which a parasite passed through as larva or during asexual phases of development
What is a suitable treatment for Strongyloides?
Ibermectin
what is the prepatent period of Whipworms?
3 months
Can humans get a Toxocara infection(
Yes; usually children
How is Capillaria hepatica ingested?
fecal contaminant or ingestion of infected animal with an infected liver
what is a characteristic sign of Toxocara in puppies?
pot belly
True or false; areas with less bodies of water will have significantly lower cases of Heartworm
true because mosquitoes need water to reproduce and therefore transmit heartworm
How long are whipworm adults?
45-75mm
How is Pearsonema plica transmitted?
infected urine or ingestion of paratenic host
The ________ is the best criteria for distinguishing between microfilariae
shape of head
True or false; Dirofilaria can cause cirrhosis in canines
true
What Paratenic hosts does Dioctophyma use?
fish and frogs
Define larva
immature stage in the life cycle of a parasite; usually between egg and adult
What are clinical signs of Dirofilaria in Canine?
cirrhosis, pneumonitis, thrombosis, caval syndrome
True or false; Whipworms can only live in the environment for a few weeks
False. It can live for years.
Describe the life cycle of Dirofilaria immitis
Adults in pulmonary artery - produce microfilaria (L1) to be passed in blood - carried in blood up to 2 years - picked up by mosquito during blood meal - L3 deposited onto skin in mosquitos saliva during next blood meal - larva enter through bite wound - migrates to thorax L4 - become immature adults (L5) and finish in pulmonary artery, vena cava or right atrium
What size do Adult Heartworm get to be?
15-31 cm
Dioctophyma uses ______ as an intermediate host
aquatic invertebrates
How long can the Microfilaria stage of Heartworm live in the blood?
2 years
What is a Trematode?
flatworms with unsegmented, leaf-like bodies
what is a characteristic feature of the adult Whipworm?
whip shaped body
Liver failure is a direct result of ________ from Heartworm infection
caval syndrome
what are two alternative names for a Primary Host?
Definitive host or final host
why is Toxascaris of more concern than Toxocara?
it is harder to treat
What is the lifecycle of Aleurostrongylus abstrusus?
adults found in bronchioles & alveolar ducts - eggs are laid, develop to larvae, coughed up, swallowed and passed in feces
Which parasite is associated with “Puppy Breathe”?
Toxocara/Roundworm
What size do Dirofilaria microfilaria get to be?
286-340um
What is peculiar about the Strongyloides life cycle?
Once the adult females are in the small intestine, they reproduce parthogenically via mitosis and deposit eggs
Hookworms can enter the body through skin penetration. Describe this life cycle.
Dog walks on L3 - larva penetrates foot pads - enters lymphatic system - migrated to heart and through the pulmonary artery moves to the lungs - is coughed up, swallowed and resides in small intestine
Is Heartworm more of a concern in cats than it is in dogs?
It is much less common but it’s also much more serious. Cats can only handle up to 3 worms before serious problems occur. This is because canines have a proportionately larger heart for their bodies. Treatment is much riskier.
How long can Eucoleus aerophilus infections persist?
up to one year
How are Oslerus osleri and Filaroides osleri transmitted?
May be transmitted via ingestion of feces or lungs or regurgitated food containing larvae
Name the parasites we will be looking at on this test
Roundworm (Toxocara canis, Toxocara cati, Toxascaris leonina)
Hookworm (Ancylostoma tubaeforme, Ancylostoma caninum, Uncinaria stenocephala)
Whipworm (Trichuris vulpis)
Heartworm (Dirofilaria immitis)
Lungworm (Oslerus osleri, Filaroides osleri)
Pearsonema (Pearsonema plica, Capillaria hepatica, Capillaria annulata)
Kidney worm (Dioctophyma renale)
Threadworm (Strongyloides)
What is the unique shape of Ancylostoma?
Shaped like a hook on the end
What type of test is recommended for Heartworm?
Antibody tests
Give an example of a Cestode
tapeworm
Is Eucoleus aerophilus zoonoticv
yes
How big are Dioctophyma renale eggs?
75um
what is a protozoa
a single celled organism
give an example of a Trematode
flukes
True or false: During the life cycle of Trichuris vulpis, a whipworm, the eggs hatch within 30 minutes of being ingested and they pass to the large intestine
true
How can you tell the difference between Dirofilaria immitis and Dipetalonema reconditum Microfilaria?
Dirofilaria; stationary motility (wiggling but don’t move), tapered head, much thicker
Dipetalonema; progressive motility, blunt head, much thinner
what is the prepatent period?
PPP: time between infection and when laboratory tests can detect the parasite
Slugs and snails are very important intermediate hosts of what broad type of parasites
Lungworms
True or false; Microfilaria can be found in the bloodstream
True
Paragonimus kellicotti uses what intermediate host? What paratenic host?
intermediate host is the aquatic snail
paratenic host is a crayfish
How does Ancylostoma look under the skin?
varicose veins
Describe the anatomy of the adult whipworm
The posterior end is thicker than the anterior end. 2/3rds of the length of the body is almost entirely esophagus. Throughout the esophagus there is secretory cells that produce fluids that aid in moving the blood through the body
Why would we use a Fecal Smear instead of a Fecal Float?
To see motile forms of Protozoa, usually Giardia. Because it is very small and a fecal float will kill them
How long does Dioctophyma renale get?
1 meter
Respiratory parasites use what intermediate host?
earthworm
What are the two common Respiratory parasites?
Oslerus osleri and Filaroides osleri
What species does Aleurostrongylus abstrusus (lungworm) infect?
feline
Describe the life cycle of Ancylostoma
- eggs hatch on the ground
- develops into L3 where it becomes infective
- transmitted through skin penetration or ingestion
- develops to L5 in small intestine and attaches to intestinal wall where it fully matures
True or false; Strongyloides stercoralis is of the Phylum Nematoda, the Order Rhabditida and the Family Strongyloididae
true
What is the treatment of Giant Kidney Worm?
Surgical removal
what is a paratenic host?
host that helps spread the parasite at the larval stage without further larval development
Why is Preventative care for Heartworm so important?
The treatment is very long, can be painful and is risky. Killing all of the Heartworm adults too quickly causes them to clog the holes in the Heart causing embolism and death.
What are the clinical signs of Dioctophyma infection)? Why does this make it hard to diagnose?
Vague abdominal pain is the only presenting sign in canines; this can be difficult to diagnose due to the number of conditions that cause abdominal pain
What is Cercaria?
a larval stage in which a parasite passes from the intermediate host (snail) to a paratenic host (crayfish) or the final host (dog)
Development of Euculeus aeropholus (lungworms) takes _____ days and occurs in the ______ of the final host
40 days
intestine
How is a Hookworm able to penetrate the skin when a Roundworm cannot?
It is significantly smaller
Which species of Pearsonema (Capillaria) causes cirrhosis?
Capillaries hepatica
Are whipworms bloodfeeders?
yes
What is the unique feature of Strongyloides when it comes to reproduction?
They can reproduce both sexually and parthogenically (no male participation)
What is the life cycle of Ancylostoma?
Non infective eggs pass to ground in feces - L1 hatches from egg on ground - L2 - L3 (infective stage)
give an example of a Nematode
roundworm
What type of dog are Respiratory parasites most common in?
greyhounds or racing dogs
what is the difference between a vector and a fomite?
vector is an animal that transmits the organism of disease (like an intermediate host)
fomite is an inanimate object that spreads disease such as a doorknob
What do mosquitos need to live in a specific area?
Bodies of water
What is Caval syndrome as it relates to Heartworm?
Manifestation of Heartworm occurring in the right side of the heart that intertwine around and pass through Tricuspid valve (associated with number of worms)
what is a common Brand Name of a drug used to treat Toxocara?
Strongid
What is Miracidium?
a larval stage in which a parasite passes from the egg to its intermediate host (snail)
Capillara annulata is also known as the _________ worm. Why?
The Crop Worm. It is often found in the crop of birds
Define Endoparasites
Internal parasites
How is Dirofilaria transmitted?
mosquito
True or false; Heartworm adults can only be found in the heart
False; they can be found in the lungs
What are 3 conditions that increase the chance of a Heartworm infection?
- dogs outdoors a lot especially at dusk and dawn
- living in areas with large mosquito population
- living in areas with warm temperatures
What are some examples of medications you might use for Heartworm prevention?
Ivermectin “Heartgard”
Milbemycon “Sentinel”
Moxidextin “Revolution”
What is the public health concern of Strongyloides?
It is very rare in humans but very serious because it can persist for decades or longer
Aleurostrongylus abstrusus uses what intermediate host? what paratenic host might is use?
Slugs and snails
Might use mice and birds as a paratenic host
What are two clinical conditions caused by respiratory parasites?
Bronchitis & tracheitis
Adult Dioctophyma renale can live for up to _________
5 years
The older the dog the more likely _________ migration of Ancylostoma will occur
somatic
What are clinical signs of Dirofilaria in Feline?
Respiratory distress, vomiting, weight loss
How can you tell the difference between the male and female adult Heartworm and Whipworm?
males have a coiled tail
True or false; Microfilaria are injected into the body by infected mosquitos during a blood meal
False; they are deposited onto the skin during the bloodmeal and they migrate into the body through the bite wound
Define Ectoparasites
External parasites
During what life stage is the only stage that Whipworms are infective?
larval
What is a characteristic feature of the Ancylostoma adult?
6 large teeth
how is roundworm transmitted?
direct transmission; ingestion of egg or ingestion of paratenic host
Pearsonema usually develops as an infection of the __________
bladder
Where does Dioctophyma renale reside?
usually right kidney but could be both kidneys
What is a good Heartworm medication for preventative care?
Revolution
What is the common name for Strongyloides?
Threadworm (less commonly Pinworm)
True or false; dioctophyma eggs are always found in the urine
false; only if the worm has found its way into the kidney
Symptoms of a whipworm infestation mimic the symptoms of what disease?
Addison’s disease
