Parasitology Exam 1 - Lecture 9 (Intro to Nemarodes)

Question 1

Discuss the difference between the direct and indirect lifecycle in regards to life cycles

Answer 1

• Direct life cycle –> no intermediate host rewquired
• Indirrect life cycle: intermediate hist required

a direct life cycle means the host produces that parasite and can transmit directly to another host of the same species without any intermediate host; Indirect life cycle –> If the parasite needs to enter another host, then this is the indirect life cycle.

Question 2

Discuss the difference between the definitive host, the intermediate host, the paratenmic host, and the reservoir host

Answer 2

• Definitive host –> sexual stages occurs in this host
• Intermediate host –> asexual reproduction occurs in this host
• Paratenic host –> not necessary for parasite dvelopment but may help maintain the life cycle
• ## Resevoir host –> mauintains a partsoite in the enviornment

Question 3

Define pre patent period and incubation time

Answer 3

• Prepatent peiod –> the time from infection until parasite sexually matures (and produces eggs)
• ## Incubatinntime –> the time from infection until clinical signs appear

Question 4

Regarding hemniths, discuss how they are broke down

Answer 4

Question 5

Discuss the general nematode lifecycle in dogs

Answer 5

• The adult stage occurs in the animals (usually, in this case, a dog). The main point is that the nematode must molt several different times before it can infect the host; in moost cases, the 3rd larval stage (the 3rd molt) is required befroe the nematode can infect the dog

Question 6

Discuss the basics of the general nematode lifecycle

Answer 6

• Oviparous - lay eggs –> most nematodes are oviparous
• Vivaparous –> produyce live larva –> mostly lungowrms and filarids

Question 7

What are the different diagnostic tests for nematodes

Answer 7

• fecal smear
• fecal float
• baermann
• ## fecal sedimentation

Question 8

Discuss how to perform a fecal smear

Answer 8

Question 9

Discuss how ot perfomr a fecal float

Answer 9

• Mixing fecal sample in a high specific gravity solution allows eggs to float to surface and debris to sink to the bottom

Need a high specific gravity because this allows the eggs to float (on the top) and all other impportant stuff sinks to the bottom

Question 10

Discuss how to perfomr a Barmann diagnostic test

Answer 10

• Feak sample wrapped in gauze allows live larvae to wiggle through and gravity allows larva to settle in the bittom

this technique is mianly used to detect any oarasite that produces live larva (especialy lung worm)

Question 11

Discuss how to perform a sediment diagnostic test

Answer 11

• Mostly used for fluke idagnosis
• heavy/dense eggs sink to the bottom of container which is colllected for ID

Question 12

Discuss Antelmintics

Answer 12

Nematodes:
- pyrantel
- morantel
- macrocyclic lactones - dichlorvos
- levamisole
- monepantel
- piperazine
- melarsomine (this is only used to kill heart worm)

Cesrodes/flukes:
- praziquantel
- Clorsulonn(this is mainly used in large animals)

Broad spectrum: fenbendazole

Question 13

Discuss prevention for helminths

Answer 13

Environmental disinfection:
- clean up dog poop
- disinfect premisies

Anthelmentics as preventatives