Brainscape's Knowledge GenomeTM

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


See full index

11- FA- Gastrointestinal disease > BVD > Flashcards

BVD Flashcards

1
Q

What type of virus is BVD

A

pestivirus

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

What are the 2 types of BVD and how prevalent is it

A

BVDv Type 1: prevalent
BVDv Type 2 rare

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

Describe what you see with type 1 BVDV

A

reduced repro performance
immunosuppression
mild systemic illness

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

When is mucosal disease seen

A

end stage of PI life

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

what is seen with type 2 BVDV

A

generally severe disease often fatal, usually adults
thrombocytopenia, diarrhoea, haemorrhagic disease
RARE in UK

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

How can BVDV virus increase resp disease in calves

A

Immunosupression
more likely for IBR +RSV and M. haemolytica infections

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

What happens if non-pregnant cow gets infected with BVDV

A

transient infection

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

When do antibodies show for non-pregnant cow gets infected with BVDV

A

from 2-4 weeks and persist for several years

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

what happens if <120 days gestation cow gets infected with BVDV

A

death and reabsorption, abortion, mummification or stillbirth; if the fetus survives, then PI

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

what happens if 120-190 days gestation cow gets infected with BVDV

A

stillbirth/abortion, abnormalities in calf

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

what happens if 190+ days gestation cow gets infected with BVDV

A

normal calf

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

List 5 possible outcomes of BVDV infection in pregnent animals

A

embryo loss
congenital defects
abortion
normal calf
PI calf

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

How id PI calf created

A

BVDV crosses placenta before immune system- calf recognises it as normal so never generates antibodies

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

T/F PI can only be caused by pregnant cow getting infected with BVD

A

False
All PI dam produce PI calves

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

T/F all PI calves go on to show mucosal disease

A

False
may show no signs at all

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

How long do PI calves shed BVDV for

A

their whole lives - and shed alot of virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the signs of mucosal disease

A

weight loss
bloody D+
dehydration
ulcerative lesions in mouth and interdigital space

Fatal condition

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

How does mucosal disease occur

A

Virus mutates from non-cytopathic to cytopathic form (ie cell killing form)- occurs in PI calves

Transmission of cp strain = potential for MD in other PIs

19
Q

T/F bulls can spread BVDV

A

True
can be PI or acutely infected

20
Q

How can a bull be blood Ab positive but antigen neg but still be PI

A

virus can ‘hide’ in testicles “immunological privileged site”
only identified by semen sample

21
Q

What is a good screening test for BVDV in dairy cows

A

Viral Ag can be detected in bulk milk, from 1 PI in 300 cows

22
Q

List 2 ways to look for BVDV in calves

A

blood Ag test pre-colostrum
ear tissue sample

23
Q

Presence of virus in samples can mean….

A

Animal is PI
animal is acutely infected- Viraemia following acute infection lasts up to 2 weeks

24
Q

Describe how to demonstrate a PI animal

A

2 positive antigen tests >3 weeks apart
Usually PIs have low/no antibody levels in both samples

25
Q

What should you do if you find a PI

A

KILL IT- because shed virus alot and can’t treat

26
Q

what do you need to consider when testing a high number of cows for BVDV

A

Sensitivity and specificity of both Ab and Ag test rel. good
BUT no test is perfect…

27
Q

Describe the Blood sampling heifer cohort method of BVDV herd monitoring

A

Blood sample for Ab from ~ 8 months of age (maternal Ab)- sample 8-10 from group
should be Ab neg

28
Q

at what level on bulk milk BVDV test shows recent or active exposure

A

> 0.7

29
Q

Describe the basic approach to BVD control

A

Evaluate current herd status
Assess the routes by which virus could enter the herd and spread within the herd
Eradication by removal of PIs and preventing new cases

30
Q

Describe how BVDV is spread

A

nose-to-nose contact main route
PIs most important sources
Faeces a poor source

31
Q

When do you vaccinate for BVD

A

must ensure protection before first breeding
Lots of vaccines avaliable

32
Q

What is the best way to eradicate BVD and prevent re-infections

A

Vaccination and monitor for PIs

33
Q

When can do nothing approach to BVD work

A

If the herd only monitor through bulk milk Ab and are consistently low/medium positive, this is still a fairly common option

But probably lots of hidden coats

34
Q

Is BVD zoonotic

A

No

35
Q

What is the main clinical sign of Bovine viral diarrhoea virus ?

1 - Dyspnoea
2 - Abortion
3 - Diarrhoea
4 - Conjunctivitis

A

2- Abortion

36
Q

Which of these is not a transmission route for BVD ?

1 - Feco-oral
2 - In-utero
3 - Milk
4 - Venereal
5 - Saliva

A

3- Milk

37
Q

Which serotype of BVDV is most common in the UK ?

1 - BVDV type 1
2 - BVDV type 2

A

1- BVDV type 1

38
Q

T/F The cytopathic form of BVDV can be transmitted to other cattle

A

False
limited to PI calves

39
Q

Bulls can be PI animals and so can be a major spread for disease in BVDV. What is the rarer form that bulls can get in which they can transmit to the to the herd ?

Virus resides in

1 - Brain
2 - Lungs
3 - Testicles
4 - Lymph nodes

A

3

40
Q

Which of these is an appropriate way of testing for BVDv on an individual basis ?

1 - Fecal PCR
2 - Blood ELISA
3 - Fecal ELISA
4 - Bulk milk tank ELISA

A

2

41
Q

What can alter testing results sensitivity when testing for PI calves ?

A

colostrum

42
Q

What is needed in order to diagnose a PI calf ?

1 - 1 x positive antigen and negative antibody test
2 - 2 x positive antigen and negative antibody tests (3 weeks apart)
3 - 2 x negative antibody tests (3 weeks apart)
4 - 2 x positive antigen tests (3 weeks apart)

A

2

43
Q

In order to sample youngstock for presence of PI calves we need to do it before colostrum is given or after at what age ?

1 - >1 month
2 - >2 months
3 - >4 months
4 - >8 months

A

4- 8 months

11- FA- Gastrointestinal disease (15 decks)

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