What Is New With BVDV Dan Grooms DVM, Ph.D Michigan State University College of Veterinary Medicine Department of Large Animal Clinical Sciences

What Is New With BVDV

Dan Grooms DVM, Ph.D

Michigan State University

College of Veterinary Medicine

Department of Large Animal Clinical Sciences

Topics To Be Covered

Information From NAHMS Dairy 2007BVDV and DeerVaccines and Fetal Protection

Programmed Approach to BVDV Control

Only 31 % of producers were “fairly” knowledgeable = opportunity to educate

Summary

BVDV knowledge - Room for improvement

High percentage of farms vaccinateHigher prevalence of BVDV in larger

herds

BVDV and Deer

Dave Richey: Detroit Free Press

BVDV and Deer

Serological evidence of BVDV infection in white tailed deer

0%

10%

Other states: 2-41% serological prevalence

BVDV and Deer

South Dakota BVDV infected deer with all the

characteristics of PI’s

Experimental Creation of PI Fawns Intranasal with “deer” strain Exposure to PI cattle Survivability appears low

IMPORTANCE?

Wildlife as a Source of Infectious Diseases

White tailed deer - cattle Bovine TB Johne’s disease Leptospirosis Salmonella

– Litchfield, Infantis, and Enteritidis (Nebraska)

Enzootic hemorrhagic disease (EHD) IBR BVDV

Need to be more aware of and manage wildlife – production animal interface

Effectiveness of BVDV Vaccines in Preventing

Fetal Infection

Fetal Protection Against BVDVStudy

VaccineVirus

ChallengeVirus

Vaccinates*

Controls*

Percent Protected

Mclurkin et al 1975 Killed 1 CP 1 12/14 0/5 86%

Harkness et al 1985 Killed 9 CP 1 7/11 0/11 64%

Meyling et al 1987 Killed 1CP 13 NCP 1

2/8 0/5 25%

Cortese et al 1998 MLV 1 NCP 1 10/12 0/10 83%

Brock et al 2001 MLV 1 NCP 2 11/19 0/6 58%

Zimmer et al 2002 Killed CP and NCP 3 NCP 1 7/9 0/15 78%

Zimmer et al 2002 Killed CP and NCP 3 NCP 1 5/15 0/15 33%

Patel et al 2002 Killed CP1 NCP 1 9/11 0/7 81%

Dean et al 2003 MLV 1 NCP 1 25/27 0/13 92%

Fairbanks et al 2004 MLV 1/2 NCP 1 18/18 0/10 100%

Fairbanks et al 2004 MLV 1/2 NCP 2 18/19 0/8 95%

Grooms 2004 Killed 1/2 NCP 1/2 11/15 0/14 73%

Experimental Infections.

What About Natural Exposure via PI’s?

Study Objective

Evaluate the ability of an inactivated BVDV vaccine to provide fetal protection in the face of continuous BVDV challenge in the form of cattle persistently infected with BVDV

Methods 60 Cross Bred Heifers

BVD Virus and Type 1 + 2 Seronegative Randomly assigned to one of two groups

Vaccinated 21 days apart (days 0 and 21) TO1 = Saline TO2 = CattleMaster® GOLD™ FP™ 5-L5

– Inactivated type1/2 BVDV antigen

Given prostaglandin on days 24 and 35 Bred by AI on days 35-44 From pregnant heifers, 15 randomly selected

from from TO1 and TO2

Methods

0 21 35-44 90 190

Day of Gestation ~1 ~50 ~150

100 day exposure

Vaccination Breeding PI Introduced Fetal Harvest

Laboratory Methods BVDV Type 1 and 2 serum virus neutralization

Dams (0, 21, 35, 63, 80, 90, 120, 150, and 190) Fetus (Day 190)

BVDV virus isolation Dams - WBC’s (Days 90, 97, 99 and 101) PI’s – Nasal swabs (Days 90, 120, and 150) Fetal tissues - Spleen, Liver, Lung, Brain (Day 190)

BVDV ELISA Fetal Skin (Day 190)

Genotyping Nested PCR

Results

PI Characterization Nasal Secretions BVDV Titer

(log10 CCID50)

Day of Study

PI # Genotype 90 120 150

9132 y Holstein Heifer

1b 4.1 1.7 4.5

405L3 y Hereford Cow

2 4.1 4.3 4.3

1632 y Holstein Heifer

1b 1.9 2.7 3.5

P171 y Crossbred Steer

2 3.5 3.1 NA

*All PI’s sourced directly from farms

Clinical FindingsAll cows remained clinically healthy 1 control (T01) heifer was diagnosed open

@ day 171 (81 days post challenge or day 130 of gestation) - no fetus recovered All other fetuses remained viable throughout

studyOne PI was euthanized 32 days after

introduction to heifers (P17 – Type 2 steer)One vaccinated heifer (T02) - Twins

BVDV Virus Neutralization

0

2

4

6

8

10

12

14

0 21 90 120 190

Geo

met

ric

Mea

n T

iter

(lo

g 2)

Control Type 1Vaccinates Type 1Control Type 2Vaccinates Type 2

1st Immunization

2nd Immunization

PI’s Introduced

Day 80 Gestation

Day 150Gestation

Virus Isolation - Dams

Virus isolation from dam WBC’s Day 0, 7, 9, 11 after PI introduction 8/15 control heifers (genotype 1 and 2) 3/15 vaccinated heifers (genotype 2 only)

*Significant reduction in BVDV viremia in vaccinated heifers (P<0.05) based on sampling protocol

Virus Isolation - Fetus

Virus isolation from fetal tissues 14/14 controls

– Genotype 1 - 8/14 (57%) – Genotype 2 – 11/14 (79%)

4/15 vaccinates – Genotype 1 - 4/4 (100%)– Genotype 2 - 2/4 (50%)

Skin ELISA 14/14 controls 4/15 vaccinates

*Significant reduction in fetal BVDV infection in vaccinated heifers (P<0.05)

>Multiple viruses found in some fetuses

Conclusion

Vaccination significantly reduced fetal infection with BVDV in a continual exposure model

Protection WAS NOT 100% emphasizing the need for ID and removal of PI’s and biosecurity in addition to vaccination

Fetal infection with multiple viruses can occur = Risk of virus rearrangement

Sahiwal

A Programmed Approach To Controlling BVDV in Dairy

Operations

Dan Grooms DVM, Ph.D



Department of Large Animal Clinical Sciences

BVDV Control Program

1. Biosecurity

2. Vaccination

3. “Seek and Destroy” PI Cattle

Ohio DairyMarch 95-May 96

0

1

2

3

4

5

6

7

Nu

mb

er

of

Ab

ort

ion

s

3 4 5 6 7 8 9

Month of gestation

BVDV NEG

BVDV POS

Sources of BVDV Exposure

PI’s or Transient Infections Replacements Exhibition Fence line Shared pastures Semen Embryo’s/Recips

Other Species Sheep/goats Camelids Cervidae Insects

Inanimate Fomites Vehicles Equipment People


1. Biosecurity

2. “Seek and Destroy” PI Cattle

3. Vaccination

MOST WANTED

Known carrier of a virulent virus…Persistently infected with BVDV

CONSIDERED ARMED AND EXTREMELY DANGEROUS

IF YOU HAVE ANY INFORMATION CONCERNING THIS PERSON, PLEASE CONTACT YOUR VETERINARIAN

REWARD

BJ

http://www.fbi.gov/homepage.htm

http://www.afit.edu/gallery/Clipart/badges/MS%20badgel.jpg

Detection of PI’s

Tests To Detect PI’s

Virus IsolationIPMA

Skin IHC/FA/ELISA

PCRIndividual/Pooled

Blood ELISA

SerologyX

Is BVDV A Problem?

Is BVDV a Problem?

BVDV is Suspected• Poor reproductive performance despite good nutrition and fertility• High calf morbidity/mortality despite good sanitation and nutrition

• Positive screening test• Laboratory confirmation of BVDV infection (virus detection or serology)

BVDV is not Suspected• Good reproductive performance

• Good calf health• Screening tests have been negative

• No laboratory evidence of BVDV infection (virus detection or serology)

BVDV Herd Screening

Herd Screening Tests

Serologyon

SentinelsBulk Tank PCR Pooled PCR

-Unvaccinated calves 6-12 m-Target cohorts

-Both Type 1 and 2

-Looks only at lactating cows-300 cows pools

-Groups of 10-100-Cost effectiveness lost when

prevalence of PI’s is >10%

Negative Positive

Individual TestingContinue Herd Screening

Necropsy

Strategies For Testing Individual Cattle For BVD PI

Dairy HerdsMultiple strategies for testing individual

animals Depending on strategy, testing will occur

over a period of time

Potential Strategies

Test everything at one timeTest new additions (expanding herd)Test new born calvesTest replacementsTest pools followed by individuals

Test all Calves and Adults w/o offspring

Assumption: Calves most likely to be PI’s

Calves serve as sentinels for dams

Pooled PCR

SkinIHC or ELISA

VI/IPMA

NegativePositive

Options: Isolate and Retest Eliminate

Positive

Individual Test

Test Dams

Record Dam as Negative

Positive Negative

If Calf

If Calf

Pregnant cows/heifers

may be carrying PI fetuses.

Must test newborn calves ASAP.

Retain in Herd

I f P o sit ive -B V D V P I

If N eg a tive -R e eva lu a te

If P o sit ive -R e tes t in 2 -3 w e e ks

D a m is n eg a tive

If N eg a tive -B V D V F ree

E a r n o tch E L IS AE a r n o tch P C R

N a sa l sw a b P C R

S ch em e 1 : Te s t a ll a n im a ls o n fa rm a t o n e t im e

T e s t D am

If P o sit ive -B V D V P I






N a sa l S w a b P C R

S ch em e 2 :T es t a ll ca lve s a t b irth fo r 12 m on thsT e s t a ll b u lls

B V D V V a ccin a ted

If P o sit ive -G o to B V D V va ccin a te d sch e m e 1 o r 2

If N eg a tive -H e rd is B V D V free

R e che ck in 12 m on ths

D o B V D V T yp e 1 a nd 2 V N se ro log y on-6 -12 m o n th o ld h e ife rs

-C o w s

N o t V a cc ina te d F o r B V D V

D a iry H e rd

T e s t D am







N a sa l sw a b P C R

S ch em e 1 : Te s t ca lves a t b irthT e s t a ll re p la cem e n ts

T e s t a ll b u llsT e s t a ll co w s w /o ca lves

T e s t D am







N a sa l S w a b P C R

S ch em e 2 :T es t a ll ca lve s a t w ea n ingT e s t a ll o p e n co w s

T e s t a ll b u lls

B V D V V a ccin a ted

If P o sit ive -G o to B V D V va ccin a te d sch e m e 1 o r 2

If N eg a tive -H e rd is B V D V free

R e che ck in 12 m on ths

D o B V D V T yp e 1 a nd 2 V N se ro log y on-6 -12 m o n th o ld h e ife rs

-C o w s

N o t V a cc ina te d F o r B V D V

C o w C a lf H e rd


1. Biosecurity

2. Control Virus Exposure “Seek and Destroy” PI Cattle

3. Vaccination

BVDV-Reproduction- Vaccines Many case/field studies suggest “vaccine

failure/vaccine breaks” w/respect to reproductive disease caused by BVDV.

Experimental studies also show that BVDV vaccines are not 100% efficacious in preventing reproductive disease.

Vaccination is a Tool Not Silver Bullet

My Thoughts on BVDV Vaccines

Believe that MLV vaccines are more effective than killed vaccines Research and biology supports this opinion Killed vaccines are useful and certainly have

a role in BVDV control

My Thoughts on BVDV VaccinesNot a fan of giving MLV BVDV/IBR

vaccines to pregnant cows Two viruses known to cause fetal wastage Ideal timing is prior to breeding Maybe a better time is late in pregnancy

– Dry off– Prebreeding– Low Stress– Improved colostral antibodies

My Thoughts on BVDV VaccinesConceptually, “rotating” vaccines makes

sense, but no science to support benefitsIdea is to broaden antigenic exposure

Bovishield Gold = NADL (1) and (53637 2) Vista = Singer (1) and 125c (2) Titanium = C24V (1) and 296 (2)

Summary

Important and Prevalent virus in the dairy industry

Many clinical manifestationsControl =

Vaccination Biosecurity Seek and destroy PI’s

Case Study

1000 head rapidly expanding dairy Raises no replacements

Consulted because of high incidence of abortions – 10%

Vaccine program Erratic Killed type 1 vaccine

Case Study

Step 1 – What is causing abortion?Submitted fetusesBulk tank milk PCR for BVDVResults

6 fetuses submitted – 3 positive for type 2 BVDV. No other conclusive findings.

Bulk tank positive for BVDV

Case Study

Step 2 – Find PI’sElected to screen entire adult herd for

BVDV 1 PI found in adult herd

Started screening calves at birth ~0.5% incidence over next 12 months

Case StudyStep 3 - Management

Screen all incoming heifers/cows and newborn calves– Incoming = 0.2% incidence– Calves = 0.5% incidence

Initially, vaccinated entire herd with type 1/2 killed vaccine

Switched to MLV type1/2 vaccine prebreeding and at dryoff

Case Study

Results Abortion incidence has dropped to ~2%

Come on Dr. Grooms, get off the ivory tower

kick..give us some good take home stuff…How can we really tell if we’ve got

BVDV?

Top 10 Reasons You Know You Have BVDV

When your carcass compost pile doubles as a sled riding hill for the kids!!



When every animal is walking around with strange looking v-shaped notch in their ear.




When your drug rep say “It can’t be BVDV, you used our vaccine”.




When your drug rep say “It can’t be BVDV, you used my vaccine”.

When you walk into the calf barn and every calf looks like Michael Jackson!!!!.




When your drug rep say “It can’t be BVDV, you used my vaccine”.

When you walk into the calf barn and every calf looks like Michael Jackson!!!!.

When you think BVD stands for “Bad Veterinary Disease”

Dr. Grooms DVM BVD

When your pregnancy rate is approaching the approval rating of George W.


When your pregnancy rate is approaching the approval rating of Dick Cheney.

When your nutritionist blames poor health on your previous nutritionist who blamed it on his/her predecessor who blamed it on...........




When you have cattle on your farm named “Runt”, “Pipsqueak”, “Shorty”, “Wobbles”,“Tiny”, “Clutzo” and “Nubby”.


Will I ever grow up!!




When you’ve just won a million dollar law suit against the electric company because of “stray voltage”, but herd health still stinks.





When you’ve just won a million dollar law suit against the electric company because of “stray voltage”, but herd health still stinks.

You’ve lost everything but your


Dan Grooms DVM PhD



517-432-1494

[email protected]

Just call me typhoid Bubba!

Documents

What Is New With BVDV Dan Grooms DVM, Ph.D Michigan State University College of Veterinary Medicine Department of Large Animal Clinical Sciences