Brainscape's Knowledge GenomeTM

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


See full index

Parasitology > Lecture 6 and 7 > Flashcards

Lecture 6 and 7 Flashcards

1
Q

What is a common parasite in grazing ruminants

A

Gastrointestinal stongylosis

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

What does the pathogenesis of Gastrointestinal stongylosis depend on

A

Climatic change, age of host, season

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

In Gastrointestinal stongylosis, what are the production losses because of

A
  • Visable clinical signs: anaemia, diarrhoea, anorexia
  • Less visible clinical signs: decresased weight gain, decreased milk yield, decreased fertility, increased prodctuion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a big problem with Gastrointestinal stongylosis

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

What are the important Gastrointestinal stongylosis in sheep and goats

A
  • Haemonchus contortus
  • Trichostrongylus
  • Teladorsagia/Ostertagia circumcincta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the important Gastrointestinal stongylosis in Cattle

A
  • Ostertagia ostertagi
  • Trichostrongylus axei
  • Cooperia oncophora
    *
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the lifecycle for Gastrointestinal stongylosis

A
  • Generally simialr for all species
  • Developmet of larvae (L1-L3) develop in faeces
  • L3 - infective stage
    • Retain the cuticle/sheath of L2 -> confer resisyance
    • Leave the faeces -> moves on the grass to be ingested by host
    • L3 are more resistant than the previous stages to desiccation and extreme temperatures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What climate factors play and important

A

Temperature and humidity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the free living stages divided into

A
  • Development of the egg ot L3
  • Survival and infection/death of L3
    • L3 survive best with lower temperature and high mositure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is important with L3

A

Rain - leave faeces and move on to the pasture. RAIN isn NB to break down the faeces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When does arrested development happen

A

Early L4 - remain dormant for several months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the success of a parasite depend on

A
  • Resistance/persistence. of larve on the pasture
  • Persistence of worms within the host when external conditions are unsuitable for survival
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the epidemiology of GI strongylosis

A
  • Almost all ruminants that are grazing are infected with GIS but their effects on the heapth and productions of the host depends on the levelof infection
  • Effects of weather and pasture conditions on the developmet and survival of the larvae -> the abundance of the larvae on the pasture when to drench, when to graze
  • The development and the survival of parasites in the host, hypobiosis and the egg production
  • Effects of changes inhost resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain the epidemiology triangle

A
  • Environemnt
  • Host
  • Parasite
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is resilience

A
  • The ability of animlas to maintain acceptable measures of productivity in spite of habouring ‘normal’ levels of parasites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Explain Resistance

A

The ability of animals to reduce their parasitic burden, either by preventing larval establishment or by removing established worms more quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain the differences between sheep and cattle worms

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the factors that affect worm population

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Explain the distribution of GIS in Australia

A
  • Effect of environmental factors on the free living stages of pasture will determine
    • Geographical and temporal distribution
      • Common and significant in higher and uniform rainfall areas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does susceptibility depend on

A
  • Age
  • Genetic factors
  • Condition of the host
  • Nutrition
22
Q

Source of contamination

A
  • Infected animals: pass in their faeces
    • Young animals are generally heavily infected and deposit large number of eggs
    • Adult animals properly fed might deposit a small number of eggs
  • Number of eggs deposited depends on
    • Species of parasite
    • Immune response
    • Season
23
Q

What are the sources of larvae on pasture in spring

A
  • Carryover L3
  • Lactating ewes are the contaminator of pasture
    • Lamb-at-foot most susceptible
    • Weaners very susceptible
24
Q

How are host infected with GI strongylosis

A
  • Orally by L3 from pasture
25
Q

Factors that favour GI strongylosis infection

A
  • Season/weather
  • Crowding
  • Nutrition
  • Introduction of young/naive animals on heavily infested pastures
26
Q

What parasite is this

A

Haemonchus contortus

Barber’s pole worm

27
Q

What is the most important endoparasite of sheep and goats in summer tainfall areas

A
  • Harmonchus contortus
    • Huge population develop in a short amount of time when conditons are favorable
28
Q

What is the morphology of haemonchus contortus

A
  • Females look like barber’s pole
  • Anterior end: small mouth with tooth
  • Posterior end: convered by a prominent flap that is tongue shaped (female), large bursa has larger lateral lobes and small asymmertrical dorsal lobe - dorsal ray is Y shaped (male)
29
Q

What is this egg from

A

Haemonchus contortus

30
Q

What is the epidemiology of haemonchus contortus

A
  • Predominant in summer rainfall areas: increase in spring, maximum in Feb then decline
31
Q

What is the optimum temp for haemonchus contortus developemt

A
  • 25-35 degrees
  • Larve don’t develop at temperatures lower than 10 degrees
32
Q

What do the larval stages of haemonchus contortus have low resistance to

A
  • Dehydration
  • Low temperatures
  • (like warm, moist summers)
33
Q

What are the pathogenic stages of haemonchus contortus

A

L4 and adults

34
Q

How do haemonchus contortus feed

A
  • Parasites make cutting movement at host tissues with its tooth and feeds on the released blood, cell contents and fluid
    • Blood sucking begins at L4
35
Q

Why do sheep get bottle jaw with haemonchus contortus

A
  • Loss of serum proteins -> decrease of osmotic pressure -> bottle jaw
36
Q

Effects of haemonchus contortus

A
  • Anaemia
  • Abomasal content is usally fluid and dark red-brown, because of presence of blood
  • Abomasal folds are edematous with focal areas of hemorrhage on the surface
  • Hypoproteinaemia
  • Reduced excercise tolerance, weakness -> leg behind the mob, refuse to move -> fall behind
37
Q

What is the epidemiology of haemonchus placei

A
  • Common in summer rainfall areas of NSW, QLD, NT and kimberly region of WA
  • Infections are common in summer and autumn
38
Q

What are the clinical signs of haemonchus placei

A
  • Dairy calves (4-12 months), beef calves during the first year after weaning
  • Anaemia, hypoproteinemia -> submandibular oedema
  • Weakness, weightloss, unthriftiness
39
Q

What parasite does this

A

haemonchus placei

40
Q

What parasite causes this

A

Ostertagia/Teladorsagia

41
Q

What aninals does Ostertagia ostertagi affect

A

Cattle

42
Q

What animal does Teladorsagia circumcincta affect

A
  • Sheep and goats
43
Q

What is the lifecycle of Ostertagia

A
  • Female worm can produce 100-200 eggs daily
  • Larave development takes place between 5-35 degrees
44
Q

How are cattle infected with Ostertagia

A

Ingeted L3

  • Enter glands in the abomasum where they elict nodules and swelling -> L4 that either emerge to lumen and continue development or may arrest early L4
45
Q

What is the pathology of Ostertagia

A
  • Associated with the emeregence of the worm from gastric glands/nodules
  • Hyperplasia of cells producing mucus - umbilicated nodules
    • Pale nodules with depressed centre
    • Hyperaemia, oedema
  • Reduction of gastric secretion -> increase in abomasal pH
  • The cell junction between epithelial cells are altered
  • Enhanced permeability of the bowel wall to amrcomolecules
  • Increase in blood pepsinogen and gastrin levels
  • Hypoalbuminemia
  • Energence of the worms from the glands is followed by necrosis and sloughing of the surfcae epithelial cells -> dipteric membranes
46
Q

What are the clinical sings of Ostertagiosis type I

A
  • Due to acquisition of large number of L3 and direct development of large number of adults over a relatively short period of time
  • Seen in animals on pasture 3-4 weeks after the availability of large number of infective larvage
  • Anorexia, watery diarrhoea, rapid weight loss
    *
47
Q

What are the clincial signs of Type II Ostertagiosis

A
  • Due to the synchronous matureation and emergence of large numbers of hypobiotic larvae from the mucosa
  • Occurs in older animals
  • It may occur when the intake of larvae is low or nonexistent
  • Rapid onset; it affects only a number of cattle in a herd
48
Q

What is Teladorsagia

A
  • Mainly a problem in young sheep and contributes to weaner ill-thrift
  • Main signs are scouring, loss of condition, anorexia and death
  • On necropsy raised pin-point white foci in the abomasal mucosa
49
Q

What is shown

A

Trichostrongylus

50
Q

What is the morphology of Trichostrongylus

A
  • Small
  • Excretory pore in sonspicuous ventral notch
  • Male: the spicules are short, brown, stout, ridged
  • Female may deposit 100-200 eggs/day
  • Optimal temperature 25 degrees
  • Perpatent period 15-21 days
51
Q

What are the clincal features with Trichostrongylus

A
  • Pathology associated with thousands of parasites
  • Anorexia, decreases in weight gain, dark-coloured diarrhoea
  • Villus atrophy, erosions, leakage of plasma proteins into the lumen

Parasitology (9 decks)

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