Brainscape's Knowledge GenomeTM

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


See full index

PMVPH > Clinical parasitology in grazing animals > Flashcards

Clinical parasitology in grazing animals Flashcards

1
Q

What are 4 important internal parasites in grazing animals?

A

Nematodes (all spp)
Liver fluke (ruminants including camelids)
Lungworm
Coccidia

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

What are important features of a NEMATODE lifecycle?

A

PPP 3 weeks
Best larval development when warm and moist (late summer/early autumn)
Larvae survive freezing, not dessication

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

Outline liver fluke/trematode LC.

A

Egg (in faeces) –> miracidium (enters snail) –> Sporocyct –> redia –> cercariae (out of snail, onto vegetation) –> metacercaria (encysts on vegetation) –> eaten and develops into mature fluke in liver.

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

What % of nematode population live within host?

A

Small amount as 95% larvae live in bottom inch of herbage.

N.b. 80% eggs are passed by 20% animals

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

What is ‘Targeted Collective Treatment’?

A

when you treat only the animals which are infected.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Outline the succession of species of worm in grazing animals

A

NOHT

Nematodirus battus, Teladorsagia (Ostertagia), Haemonchus, Trichstrongylus and fluke (acute, chronic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which worm has a barber’s pole appearance?

A

Haemonchus

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

When do you see acute and chronic fluke?

A 
Acute = Sep-Dec
Chronic = Jan-Mar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the major parasites of ruminants?

A 
NEMATODES:
Teladorsagia (sheep)
Ostertagia (cattle)
Haemonchus
Trichostronglus
Nematodirus

TREMATODES
Fasciola hepatica

CESTODES;
Moniezia

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

What is the ‘HOT’ acronym?

A

Reflects size of nematode parasites found in ruminant abomasum:
Haemonchus - 2cm
Ostertagia (cattle) - 1cm
Teladorsagia (sheep) - 0.5cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where are Trichostrongylus and Nematodirus found anatomically?

A

Small intestine

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

What are the harmful effects of nematodes?

A

CLINICAL - diarrhoea, weight loss, death

SUB-CLINICAL - reduced weight gain, all grazing animals, LOP

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

What is the mechanism of nematode harmful effects?

A 
Reduced appetite (70% drop in DMI and weight gain)
Altered gut structure and function
Immune and inflammatory responses
Malabsorption
Energy cost of I.R.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why does protein loss occur in PGE? 4

A

Increased secretion of mucous and IgA
Increased cell turnover in mucosa
Increased mucosal permeability
Local Ag/Ab reaction in gut –> local vasodilation

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

What is the FAMACHA Test?

A

provides a semi-quantitative assessment of anaemia (e.g. caused by Haemonchus). A colour chart is held up against MM to classiy level of anaemia. Aim is to decrease amount of ATHM. used to decrease resistance risk.

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

What effects can trematodes cause?

A

ACUTE - liver damage, high number of fluke

CHRONIC - blood and protein loss. Hyperplasia of bile ducts

17
Q

How might the harmful effects differ between growing and adult animals?

A 
GROWING:
reduced weight gain/weight loss
poorer FCR
\+/- anaemia
death

ADULT:
weight loss and poor BCS
+/- decreased reproductive performance
decreased milk/wool production and performance

18
Q

Adult host immunity is good except in which instances? 4

A

Goats
If immuno-compromised
PPRI (due to IgA–> mammary gland, ewes especially)
Liver fluke (always poor immunity versus this)

19
Q

What is the source of parasites in the spring?

A

over wintered larvae on pasture - major source

larvae from adult animals - minor source

20
Q

What are the main parasite threats in spring?

A

N. battus (overwintered eggs)

Type 2 Ostertagiasis in young cattle (late winter really)

21
Q

When do liver fluke eggs start to hatch?

A

Summer

22
Q

What are the main parasite threats in summer?

A

Nematodes - calves, lambs, goats
Lambs/goats - primarily Telodorsagia
Subclinical effect of bovine PGE/bovine ostertagiosis

23
Q

When do pasture larval levels peak?

A

Autumn

24
Q

When do liver fluke metacercariae enter snails?

A

Autumn

25
Q

What are the main parasite threats in autumn?

A

Nematodes (calves, lambs, goats)
Sheep/goat - primarily Trichostrongylus
Subclinical effects - PGE

26
Q

What is acute fasciolosis?

A

From ingestion of millions of metacercariae –> immature fluke tracks in liver. If there are many of these, liver failure will ensue.

27
Q

How can endoparasites be controlled? 4

A

Limit exposure of susceptible animals to large numbers of larvae
Anthelmintics to break parasite LC
‘Safe’ pasture
Minimise numbers of susceptible animals

28
Q

What is SCOPS?

A

Sustainable Control of Parasites in sheep

Best advice to use, many farmers follow this

29
Q

What is COW?

A

Control of Worms Sustainably

in cattle

30
Q

What are the different classes of anthelmintics?

A 
Yellow - Leavmisoles 
White - Benzimidazoles
Clear - ML
Orange - amino-acetonitrile derivatives
Purple - spiroindoles
31
Q

How can you detect anthelmintic resistance? 3

A
  1. ) Post-dosing FEC (‘drench tests’)
  2. ) FECRT
  3. ) LDTs and EHAs
32
Q

For drench tests, how long after treatment do you need to wait to take a faecal sample from sheep?

A

7 days (2-LV)
10-14 days (1-BZ)
14-16 days (3-ML)

33
Q

What does the drench test detect?

A

Anthelmintic inefficacy, no AR per se.

34
Q

When is AR suspected after a FECRT?

A

When the percentage reduction in FEC of a test group compared with the controls is <95%

35
Q

What happens in a simpliefied FECRT?

A

The pre-dose FECs aren’t performed, results are just based on percentage reduction in mean FEC in treatment groups versus controls.

36
Q

What are LDTs and HEAs?

A

Larval Development Tests - for 1-BZ and 2-LV anthelmintics

Egg Hatch Assays - for 1-BZ anthelmintics

37
Q

How does AR vary on a farm?

A

season, worm species present at time of teset and test’s specificity and sensitivity in detecting resistant alleles in worm population

38
Q

What are the SCOPS guidelines?

A

Weigh and dose appropriately
Calibrate and maintain equipment
Drench and inject correctly
Storage (between 4-25 degrees, ensure you shake well - especially white products e.g. BZ).

39
Q

Where to inject an anthelmintic?

A

SUBCUTANEOUS - skin of neck under ear by 10-15cm, 1.6cm needle
MUSCULAR - mid neck with 2.5-4cm needle aiming upwards and inwards

PMVPH (33 decks)

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