BVDV

Question 1

What type of virus is BVDV?

Answer 1

Pestivirus (family flaviviridae) - RNA virus

Question 2

Describe the virus classification for BVDV:

Answer 2

1. Either type 1 or type 2 based on genotype
2. Both types exist as either a cytopathic or a non-cytopathic biotype
3. Biotype doesn’t indicate virulence (only indicate how it acts in the tissue)

Question 3

For acute BVDV:

1. Describe the signalment of cattle affected
2. What are the clinical signs?

Answer 3

1. 6 - 24 months of age
2. Fever, leukopenia, damages epithelial surfaces, can cause immunosuppression and ammonia

Question 4

How does BVDV cause haemorrhage syndrome?

Answer 4

• Typically induces a thrombocytopaenia

Question 5

What is the most likely outcome of a heifer infected with BVDV between 100-150 days of gestation?

Answer 5

• hydrocephalus
• cerebellar hypoplasia
• hypomyelinogenesis
• ocular defects
• hypertrichosis
• brachygnathia

Question 6

What happens with a heifer that is infected between 40-125 days of gestation?

Answer 6

• Foetus is immunotolerant and survives → become PI animals (main way it is maintained in the herd)

Question 7

How does mucosal disease or chronic BVDV occur?

Answer 7

• Pi animal is superinfected with CP biotype or the NCP turns to CP - mucosal disease is usually per acute and fatal

Question 8

How is diagnosis of BVDV typically done?

Answer 8

Based on antigen testing:

• Fluorescent Ab
• PCR/serology
• Ag capture ELIZA
• ELIZA/serology
• IHC (ear notch)

Question 9

What are the two principles of managing BVDV?

Answer 9

• Detection and elimination of PI’s
• Vaccination