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 2007 BVDV and Deer Vaccines 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 vaccinate Higher prevalence of BVDV in larger herds

Dave Richey: Detroit Free Press BVDV and Deer Dave Richey: Detroit Free Press

Other states: 2-41% serological prevalence BVDV and Deer Serological evidence of BVDV infection in white tailed deer 0% 10% Other states: 2-41% serological prevalence

BVDV and Deer IMPORTANCE? 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 BVDV Study Vaccine Virus Challenge 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 3 NCP 1 2/8 25% Cortese et al 1998 MLV 1 NCP 1 10/12 0/10 83% Brock et al 2001 NCP 2 11/19 0/6 58% Zimmer et al 2002 Killed CP and NCP 7/9 0/15 78% 5/15 33% Patel et al 2002 Killed CP1 9/11 0/7 81% Dean et al 2003 25/27 0/13 92% Fairbanks et al 2004 MLV 1/2 18/18 100% 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? Again, several studies have attempted to answer this question and peer reviewed studies using commercial vaccines are outlined above In general, it is apparent that fetal protection is not 100%. To date, only one study has has a used a type 2 challenge following a type 1 vaccine (Brock et al) and protection in this study was ~58%.

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 Our objective of this study was to 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, thus replicating what is more likely to occur in a real world situation.

Methods 60 Cross Bred Heifers Vaccinated 21 days apart (days 0 and 21) 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 To do this, 60 cross bred heifers were sourced. All heifers were free of BVD virus and neutralizing antibodies to both type 1 and 2 BVDV. The heifers were randomly allotted to two groups, a control group designated as T01 and a vaccinated group, designated as T02. At day 0 and 21 of the study, the control group was injected with saline while the vaccinated group was immunized with a commercially available 4-way virus vaccine containing inactivated type 1 and 2 BVDV. The heifers were then estrous synchronized using two injections of Lutalyse 11 days apart. Starting on day 35 after the second Lutalyse shot and continuing until day 44, all heifers were then bred artificially. Heifers were confirmed pregnant at day 40 at which point 15 controls and 15 vaccinated heifers were randomly selected to continue in the study.

Methods Vaccination Breeding PI Introduced Fetal Harvest 0 21 35-44 90 190 Day of Gestation ~1 ~50 ~150 100 day exposure To review the time line….

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 Laboratory methods that were used included the following. Type 1 and 2 BVDV serum virus neutralization was performed on the dams at days 0, 21, 35, 63, 80, 90, 120, 150, and 190 and the harvested fetuses. Virus isolation was performed on WBC’s from dams at days 90, 97, 99 and 101 which corresponded to days 0, 7, 9 and 11 post PI introduction. Virus isolation and titration was performed on nasal swabs taken from PI’s on days 90, 120, and 150. At fetal harvest, virus isolation was attempted from fetal spleen, liver lung and brain and an antigen capture ELISA was performed on fetal skin Finally, any virus that was isolated was genotyped as type one 1 or 2 using a nested PCR

Results

PI Characterization Nasal Secretions BVDV Titer (log10 CCID50) Day of Study PI # Genotype 90 120 150 913 2 y Holstein Heifer 1b 4.1 1.7 4.5 405L 3 y Hereford Cow 2 4.3 163 1.9 2.7 3.5 P17 1 y Crossbred Steer 3.1 NA First, I would like to describe the PI’s used in this study. First a note about these animals. Al were derived acquired from farms in the Midwest after being found on routine virus screening. So these animals closely represent virus that are actively circulating in the field at the time the study was conducted. 913 and 163 were both recently calved Holstein heifers from the same farm and their persistent BVDV was genotype 1. 405L was a 3 year old Hereford cow from a seed stock operation and P17 was a yearling steer acquired from a feedlot which at the time was screening incoming cattle. Both of these animals were BVDV genotype 2. During the study tvirus titers in nasal secretions varied, but was always detectable. Also, P17 became ill 15 days after being commingled with the heifers and was humanely euthanized 17 days later. *All PI’s sourced directly from farms

Clinical Findings All 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 study One PI was euthanized 32 days after introduction to heifers (P17 – Type 2 steer) One vaccinated heifer (T02) - Twins

BVDV Virus Neutralization This chart depicts type 1 and 2 BVDV serum neutralization titers. Please note that what is being shown is the log to the base 2 titers. Some important notes. First, all animals were negative for BVDV antibodies prior to immunization. When the PI’s were introduced, the vaccinated heifers had significant titers to both type 1 and type 2 BVDV while the controls were still negative. Within 30 days of PI introduction, both the control and vaccinated animals had a significant increase in both type 1 and 2 titers, indicating virus exposure had occurred, and these increased titers were maintained to the conclusion of the study 1st Immunization 2nd Immunization PI’s Introduced Day 80 Gestation Day 150 Gestation

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) After introduction of PI’s, virus was isolated from Dam buffy coats from 8/15 control heifers and 3 of 15 vaccinated heifers, which was significantly different. It is likely that if we had increased the frequency of our sampling schedule, the number of heifers which were positive would have increased. However, since the primary outcome we were interested in was fetal infection, more frequent sampling was felt to be unnecessary. *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 *Significant reduction in fetal BVDV infection in vaccinated heifers (P<0.05) Finally, at fetal harvest, BVDV was isolated from fetuses derived from all control heifers and 4 of the 15 vaccinated heifers.. The same results were found with the antigen capture ELISA using fetal skin. Both genotypes of virus was isolated from fetus derived from the control and vaccinated heifers. Interestingly, in 6 of the control and 2 of the vaccinated heifers, both type 1 and 2 virus was isolated suggesting a dual infection >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 Our conclusions from this study – Vaccination with a commercially available multivalent vaccine containing an inactivated BVDV fraction can significantly reduce fetal infection with BVDV However, protection is not complete, emphasizing the need for biosecurity and PI detection as in conjunction with a sound vaccination program.

Sahiwal

A Programmed Approach To Controlling BVDV in Dairy Operations Dan Grooms DVM, Ph.D Michigan State University College of Veterinary Medicine Department of Large Animal Clinical Sciences

BVDV Control Program Biosecurity Vaccination “Seek and Destroy” PI Cattle

Ohio Dairy March 95-May 96

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

BVDV Control Program Biosecurity “Seek and Destroy” PI Cattle 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

X Detection of PI’s Tests To Detect PI’s Virus Isolation IPMA Skin IHC/FA/ELISA PCR Individual/Pooled Blood ELISA X Serology

Is BVDV A Problem?

BVDV is Suspected Is BVDV a Problem? BVDV is not 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) Is BVDV a Problem? 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

Continue Herd Screening Individual Testing Herd Screening Tests Necropsy Serology on Sentinels Bulk 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 Continue Herd Screening Individual Testing

Strategies For Testing Individual Cattle For BVD PI

Dairy Herds Multiple strategies for testing individual animals Depending on strategy, testing will occur over a period of time

Potential Strategies Test everything at one time Test new additions (expanding herd) Test new born calves Test replacements Test pools followed by individuals

Test all Calves and Adults w/o offspring Pregnant cows/heifers may be carrying PI fetuses. Must test newborn calves ASAP. Test all Calves and Adults w/o offspring Assumption: Calves most likely to be PI’s Calves serve as sentinels for dams VI/IPMA Skin IHC or ELISA Pooled PCR Retain in Herd Positive If Calf Positive Negative Individual Test Record Dam as Negative If Calf Options: Isolate and Retest Eliminate Test Dams Positive Negative

BVDV Control Program Biosecurity Control Virus Exposure Vaccination “Seek and Destroy” PI Cattle 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 Vaccines Not 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 Vaccines Conceptually, “rotating” vaccines makes sense, but no science to support benefits Idea 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 manifestations Control = 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 fetuses Bulk tank milk PCR for BVDV Results 6 fetuses submitted – 3 positive for type 2 BVDV. No other conclusive findings. Bulk tank positive for BVDV

Case Study Step 2 – Find PI’s Elected 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 Study Step 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 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!!

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.

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”.

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

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 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

Top 10 Reasons You Know You Have BVDV When your pregnancy rate is approaching the approval rating of George W.

Top 10 Reasons You Know You Have BVDV 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...........

Top 10 Reasons You Know You Have BVDV 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!!

Top 10 Reasons You Know You Have BVDV 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”. When you’ve just won a million dollar law suit against the electric company because of “stray voltage”, but herd health still stinks.

Top 10 Reasons You Know You Have BVDV 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”. 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

Michigan State University College of Veterinary Medicine Dan Grooms DVM PhD Michigan State University College of Veterinary Medicine 517-432-1494 groomsd@cvm.msu.edu

Just call me typhoid Bubba!