1. Importance of Bovine Leukosis (Bovine Leukemia Virus)
Antibody presence is considered evidence of infection
Infection is usually inapparent and persistent
Fatal Adult Lymphosarcoma
Most common tumor of cattle
Tumors in:
Lymph nodes
Spinal chord
Heart
Kidney
Spleen
Intestines
Abomasum
Tissue behind the eye
Uterus
Type II BVDV Abortion rate 44% (3-83%)

3. Multiple Causation of Disease
Host
Health
Disease
Pathogen
Environment

4. Economic losses due to:
Death of cattle
Carcass condemnation
Premature culling and replacement

5. Control of BLV? 1
Understand that transmission is possible through blood contamination via:
Insects
Blood transfusions
Common needles or surgical instruments
Contaminated palpation sleeves

6. Control of BLV? 1
Understand that transmission is possible through blood contamination 2
Understand that transmission from dam to offspring can happen

7. Control of BLV? 1
Understand that transmission is possible through blood contamination 2
Understand that transmission from dam to offspring can happen
Segregate seropositive (infected) animals from seronegative (uninfected) animals with at least 1 fence (10 feet preferred). 3

8. Importance of Bovine Viral Diarrhea
Consequences of in
utero
BVDV infections
Type II BVDV Abortion rate 44% (3-83%)
Infertility
Day 0 of gestation
150 days
birth

9. Importance of BVDV Consequences of in utero BVDV infections
BVDV isolated from 18 fetuses, 14/18 aborted in the last 3 months. (Dan Grooms, 2004)
Type II BVDV Abortion rate 44% (3-83%)
Abortion
Infertility
Day 0 of gestation
150 days
birth

10. Importance of BVDV Consequences of in utero BVDV infections
Persistent infection
Noncytopathic BVDV
Consequences of in
utero
BVDV infections
Type II BVDV Abortion rate 44% (3-83%)
Abortion
Infertility
Day 0 of gestation
150 days
birth

11. Importance of BVDV Consequences of in utero BVDV infections
Congenital defects
Importance of BVDV
Persistent infection
Noncytopathic BVDV
Consequences of in
utero
BVDV infections
Type II BVDV Abortion rate 44% (3-83%)
Abortion
Infertility
Day 0 of gestation
150 days
birth

13. Importance of BVDV Consequences of in utero BVDV infections
Congenital defects
Importance of BVDV
Persistent infection
Noncytopathic BVDV
Consequences of in
utero
BVDV infections
Acute infection
Type II BVDV Abortion rate 44% (3-83%)
Abortion
Infertility
Day 0 of gestation
150 days
birth

14. Importance of BVDV Depression Anorexia Diarrhea
Ulcers of the nose, mouth, and muzzle
Hemorrhagic disease
Acute death
Total annual losses per calving:
$20 with low-virulence strains
$57 with high-virulence strains
Acute death Type II average mortality 25% (5-43%)
<2 years old average mortality 53% (13-100%)
A 2002 study in the Maritime provinces of Canada identified a $1,525 average annual loss in 50 cow dairy herds infected with BVDV.
A 1995 study in Michigan dairy herds identified that 15% of herds contained a PI animal.
When Acute infections reach 34%…total annual losses(Houe H, Vet Microbiol 1999; 64:135-44)

16. BVDV 1 Surveillance to detect How???
Clinically, BVDV infections can be grouped into basically 2 groups. Acute infections may occur in any immunocompetent animal. Infection of the fetus prior to the development of immunocompetence, which occurs at approximately 125 days of gestation , may result in fetal death or lifelong, persistent, immunotolerant infections.

17. Surveillance High Risk Ear notch on all calves
Test all cows without calves
(VI on serum)
Test bulls and heifers

18. Surveillance Low risk (choose your plan)
#1. Monitor production & health
#2. Serology of herd sub-set
#3. PCR on pooled serum (entire calf crop)
#4. Ear notch test (entire calf crop)

19. A Complete Focus on BVDV1
Surveillance to detect
Vaccination to keep in check 2

20. Bovine Viral Diarrhea Virus Genome
A single large open reading frame (11,694 nt)
nonstructural gene
structural genes
nonstructural genes
Npro C
Erns E1
385 nt E2 ?
NS2-3
NS4A
NS4B
NS5A
NS5B
226 nt
5’NTR
3’NTR

21. B I OT YPE Cells infected with cytopathic BVDV
Cells infected with noncytopathic BVDV B I OT
YPE
Uninfected cells

22. Vaccination will not provide complete protection in any situation.

23. Vaccination and fetal protection
Modified-Live
Vaccination
Experimental challenge
at 75 days of gestation
% persistent infections
Vaccination will not provide complete protection in any situation.

24. BVDV vaccination protocol
Heifers at 4 to 6 months
administer MLV
revaccinate with MLV 30 days later
Revaccinate heifers and cows prior to breeding
Vaccination will not provide complete protection in any situation.

25. A Complete Focus on BVDV1
Surveillance to detect
Vaccination to keep in check
Biosecurity to protect 2 3

26. Biosecurity: Controlling the movement of1
People
Objects (fomites)
Animals 2 3

27. How to do biosecurity
Identify and remove persistently infected animals from your herd.

28. How to do biosecurity
2. Don’t introduce cattle into your herd that lack previous testing for BVDV, especially during the breeding season or the first 5 months of gestation.

29. 3. Prevent your cattle from contacting cattle outside your herd (e. g
3. Prevent your cattle from contacting cattle outside your herd (e.g. shows, exhibitions, fence-line contact), especially during the breeding season or the first 5 months of gestation.
If contact occurs with your non-pregnant animals, quarantine for 21 days before reintroduction to your herd.
If contact occurs with your pregnant animals (prior to 5 months of gestation), isolate until the calf is born and test the calf for BVDV before reintroduction to your herd.

30. How to do biosecurity
4. Don’t allow people wearing boots and coveralls contaminated by other herds to contact your cattle.

31. How to do biosecurity
Don’t allow dirty or contaminated instruments from other herds to contact your cattle (e.g. nose tongs, vaccine vials, balling guns, dehorners, castrating knives, tagging pliers)

32. How to do biosecurity Implement appropriate fly control.
Limit contact with wildlife (especially deer).

33. Don’t forget biosecurity for semen & embryos
Semen CSS certified
Embryos from BVD free donor or washed according to International Embryo Transfer Society (IETS) Protocol

34. Anaplasmosis

35. Usually no clinical signs in calves!
Signs of Anaplasmosis
Usually no clinical signs in calves!
Acute aggression
Weakness and ataxia
Fever
Off feed
Constipation with dark brown feces
Abortion

36. Control of Anaplasmosis1
Understand that transmission is possible through blood contamination via:
Insects- ticks and horse flies
Blood transfusions
Common needles or surgical instruments
Contaminated palpation sleeves

37. Control of Anaplasmosis1
Understand that transmission is possible through blood contamination 2
Understand that some cattle can be persistent, asymptomatic carriers but infect insects

38. Control of Anaplasmosis1
Understand that transmission is possible through blood contamination 2
Understand that some cattle can be persistent, asymptomatic carriers but infect insects 3
To obtain complete clearance, treat with long acting tetracycline every 3 days for 4 successive treatments & confirm clearance