Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Parasitology > Parasitology - Exam 1 Lecture 10 (ascarids) > Flashcards

Parasitology - Exam 1 Lecture 10 (ascarids) Flashcards

1
Q

Discuss ascarids - the basics

A
  • Very common
  • large nematodes
  • adults live in smallk intestine
  • some species are zoonotic
  • ## huge reproductive potential and eggs survive in envionrment for months
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What ascarids infect the different species

A
  • Toxocara canis –> dogs
  • Toxocara cati: cats
  • Toxocara leonina –> in dogs and cats and zooo animals
  • ## Baylisascaris procyonis in racoons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Illustrate the different different parasites and the organs in wgich they infect

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Discuss the Toxocara canis life cycle

A
  • Adult worms in intestines mate and produce eggs whch are pooped inot the enuivornment
  • Larva develops within the egg to the infectious L3. NOTE THAT THIS OCCURS IN THE ENVIORNMENT
  • Dog ingests larvated egg
  • Larvae hatches out in intestine and enters the blood stream:
    - some somatic migration –> encysts in tissues
    - some take tracheal route –> back to intestine to mature and produce eggs –> NOTE THAT THIS OCCURS IN THE HOST ANIMAL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Discuss thr Toxocar canis life cycle

A
  • somatic migration can occur in any malmallian host (mouse, rabit, humans, etc)
    - becomes a paratenic host whre the parasite arrests in the infective larval stage but does not develop further –> waits for the paratenic hiost to be eaten by the definitive host
  • a dog can become infected by eating a paratenic host that contains Toxocar canis arrested by larvae
    - ingestion of L3 from tissues results in patent infection in dogs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When considering Toxocara Canis, discuss the transmission

A

Four ways in which a dog can be infected:
1) ingest a larvated egg from the enivornment
2) eats an infected paratenic host
3) Transplacental transmission –> arrested L3 in the tissues of the dam are reactivated and migrate to the placenta during pregnancy > infects pups in utero
4) Transmammary transmission –> arrested L3 in the tissues of the dam are reacivated and migrate to the mammary gland > ingested by pups in the milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Again, when consideirng toxicara canis, discuss the transmision routes

A

Transplacental transmission:
- larvae migrate thorugh lungs of thr pups
- Cause damage and inflammation
- Rare but the most commonly fatal route

Transmammary transmision:
- larva ingested by pups> go straught to the small intestine and develop into adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Now, discuss the transmision and life cycle of toxocara canis

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Discuss the opathologic effects of toxocar canis

A
  • severity of clinical signs depend on hoist factors and worm burden
  • Adult worms in the intestinal tract
  • Smal numbers of intestinal worms: mild mucoidn enteritis, mild diahhrea, often asymptomatic
  • **Large numbers of intestinal worms:* obstruction or rupture of intestine, blockage of bile or pnacreatic ducts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Discuss the clinicasl signs of toxocar canis

A
  • pathogenic primarily in puppies, adults tend to be asymtpomatic
  • **adult worms ** in the inestine –> live worms in feces or vomtius
  • **larval worms ** mirgrating thorugh the lungs
  • ## General ill thrft
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Discuss the diagnsois of toxocara canis

A
  • Fecal floats to identiofy the eggs
  • fecal antigen tests
  • young puppies - presum,toive because of clinical history of dam and kennel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Discuss the life cycle of toxocara cati

A

Different toxocar canis in dogs in that 1) very few undergo somatic migration in cats –> encysts in tissues 2) **almost all ** take tracheal route –> back to intestine to mature and produce eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Discuss the transmission routes for Toxocara cati

A

Three ways in which a cat can be infected:
1) ingests a larvated eggs from the eniuvonrment
2) Eat an infected paratenic host –> THIS IS THE MAJOR TRANSMISSION ROUTE FOR TOXOCAR CATI
3) Transmammary transmision is possoible but ONLY if the queen is infected during lacrtation

TRANSPLACENTAL TRANSMISSION DOES NOT OCCUR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

DISCUSS THE DIAGNOSIS FOR TOXOCAR CATI

A

Same as Toxocara canis
fecal floats to identify the eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Discuss the species known as toxocaris Leonina and its life cycle

A

The main differences between this and that of Toxocar cati are that 1) takes less than 1 week for infectious L3 to develop in the egg –> NOTE that thiss occurs in the envornment. Next, 2) Larvae hatches out in the inestine and **molts L4 > L5, adult; also, it does not migrate in dogs and cats ** NOTEthat this occurs in dogs and cats

17
Q

discuss the basics of Toxocaris leonina transmission

A
  • Two ways in which an animnal can be infected:
  • 1) Ingest a **larvated egg ** from the enivonrment
  • 2) Eat an infected paratenic host –> this is the majior transmision route

transmammary and transplacental transmission does not occur

18
Q

Discuss Bayliascaris

A

Baykliascaris is an important zoonotic nematode
Definitive host: racoon
Life cyclke: same as Toxocara canis –> it undergoes somatic migrauion in any mammal

Larva are muych larger than T. Canis, grow as they migrate and wander aggresivekly

19
Q

why are toxocara canis and abylisacascaris considered to be important zoonotic pathogens/

A

Toxocara canis and Bayliasacris are important zoonotic pathogens

  • ## These parasites cause **visceral larval ligrans (VLM) ** and ocular larval migrans (OLM) in humans
20
Q

Discuss viceral larval migrans

A
  • usually seen in children under 5 years old
  • Damage is due to the L3 larvae migrating through the tisssues and the iummune response trying to stop them
  • ## Symptoms vary from asymptomatic to very severe –> can have cardiac, pulmonary, neurologic involvement, dpendsing on where the larvae migrate
21
Q

Discuss ocular larval migrans

A

Eosinophilic granuloma surroundsng in the larva in the retina –> can be mistaken for retinoblastoma

22
Q

Discuss control and prevent human inection in terms of ascarids

A
  • Treat pets –> deworm regualry (prevent transmission from dams to puppies; prevent puppies from shedding eggs)
  • Reduce envionmentakl contamination: recue umber of stray dogs

educate clients

23
Q

Discuss dog and puppy treatment in relation to ascarids

A

Anthelmintic arsenal:
- pyrantel maoate
- piperazine
- fenbendaz\ole
- macrocycli lactones

Treat puppies eery two weks starting at tweks old until 3 months old:
- pyrantel pamoate –> labeled for use in puppies 2 weeks and olde; treat dams at the same time

Piperazine and fenbendazole in puppies > 6 weeks old

24
Q

Again, discuss the treatment for dogs and puppies when considering Ascarids

A

Treat kactating dams to prevent transpacental and transmammary transmission –> both options are off label

1) **fenbendazole __> daily from day 42 of gestation until 14 days after whelping **
2) High dose ivermectin –> not recommended by manufacturer

25
Q

Discuss the treatment of ascarids in cats and kittens

A
  • preganant queens do not need to be treated
  • Treat both lactating queen and kittens at 2-4-6-8 weeks of age woth pyrantel pamoate
26
Q

Discuss the envionmental control of ascarids

A
  • it is really hard to kill ascarid eggs –> they are ot affected by many household cleaners
  • decrease egg shedding in envionrment –> deworm regularly
  • clean up –> dispose of feces
  • Get rid of eggs–> Bleach to remove the protein coat from the egg

Parasitology (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions