Bovine Viral Diarrhea (BVD)

1
Bovine Viral Diarrhea (BVD)

• Common viral disease of cattle that affects the
  respiratory, digestive, reproductive, lymphoid,
  and nervous system
• Caused by a pestivirus (Togaviridae)
• Occurs world wide, affects cattle of all ages,
  however most commonly seen in cattle 8-24 months
  of age.

2
BVD

• BVD is immunosuppressive
• Transmission through contact with infected cattle
  by inhalation or ingestion of infected saliva,
  nasal discharge, ocular discharge, urine or
  feces.
• Data indicates that 50-90 of cattle world wide
  have been exposed
• Currently only about 13 of cow-calf operations
  in the US vaccinate for BVD
• Animals infected with BVD during late pregnancy
  (120-150 days of pregnancy) may produce calves
  with congenital defects (cerebral hypoplasia,
  cataracts, tight curly hair or lack of hair.
• Sometimes produce calves that are referred to is
  having weak calf syndrome.

3

• Two biotypes of BVD
• Non-cytopathic BVD- has little effect on cultured
  cells.
• Cytopathic BVD- kills susceptible cell cultures.
• Persistently infected (PI) cattle are those
  animals infected in utero with non-cytopathic BVD
  during the first four months of pregnancy. These
  animals are persistently infected and either
  develop mucosal disease or chronic BVD following
  exposure to cytopathic BVD, these animals shed
  virus while alive.

4

• BVD takes on different forms
• Acute BVD
• Usually a mild disease characterized by fever,
  reduction in WBC count, and suppression of the
  immune system making the animals susceptible to
  other diseases.
• Pregnant animals usually show no clinical
  symptoms however they may abort, have fetal
  mummification, birth defects, premature calves,
  weak calves or calves with persistent BVD
  infection.
• In confined cattle or stressed cattle acute BVD
  may cause severe respiratory disease or diarrhea.

5

• Mucosal BVD
• Shows classical BVD symptoms including oral and
  gastrointestinal ulcers and diarrhea.
• Fever 104-1060F, mild bloating, anorexia,
  depression and dehydration.
• Fecal material may have blood in it from
  hemorrhaging ulcers.
• Animals can die with 48 hrs (due to severe
  dehydration caused by high fever and diarrhea).

6

• Chronic BVD
• Similar to mucosal form, occurs after persistent
  infection
• Animals die more slowly
• Chronic BVD are capable of spreading large
  amounts of the BVD virus.

7

• Atypical BVD
• New type seen in the US in dairy cattle.
• High death loss
• Symptoms include high fever, loss of appetite,
  milk production ceases, occasional diarrhea,
  respiratory distress, and death within 48 hours
  of onset.
• USDA researchers classify this as Type 2.

8
Prevention

• Vaccinate
• Be sure to follow the label, two injections of
  killed vaccine are necessary. A single initial
  dose of vaccine does not provide adequate
  protection. This vaccine can be safely
  administered to pregnant animals.
• A modified live BVD vaccine for use in
  non-pregnant animals. A single dose of vaccine
  is adequate.