Bovine Viral Diarrhea (BVD) review

BVD may infect cattle of any age.

BVD is a disease that diminishes production and in the individual impacts multiple body systems including the reproductive, respiratory, digestive and immune systems.

BVD can cause a variety of clinical and subclinical reproductive, enteric, and respiratory syndromes and immune suppression.

BVD is unique in that a fetus that is infected from its transiently or persistently viremic dam prior to formation of a competent immune system can become persistently infected (PI) with the virus.

PI animals will shed BVD from body secretions throughout their life.

PI animals are considered the primary reservoir for BVD in both cow herd and feedlot situations.

Clinical signs can vary from pneumonia, abortions, stunted calves, stillbirths, PI calves, weak calves, unthriftiness, increase disease susceptibility and full blown disease characterized by a watery diarrhea that frequently leads to death.

The virus presents in different forms, cytopathic, noncytopathic, type 1, type 2, type 1a, 1b,…………… 2a, 2b……………..etc., etc., etc.

All of this makes for confusion when selecting vaccines and testing for the disease.

The virus may exist in multiple species and transmission from one to the other may occur

Transmission and Sources of BVD

• Transmitted by, ingestion, inhalation, insects, carried on boots and vehicles


• Sources
  -transient infected animals including wildlife
  -Persistently infected animals are the main source of infection. PI’s shed viruses in high numbers and infect others, even if they are vaccinated.
  -PI calves result from the dam being exposed during the first third of pregnancy


• 
  Keys to controlling BVD
  
  -Understand “persistently infected” (PI) animals as they relate to BVD.
  -Not be willing to live with one or more PI calves in a herd.
  -Not be willing to keep a PI calf as a replacement heifer or breeding bull. (don’t sell them either)
  -Commit to finding BVD PI cattle in the herd
  

Economic Impact of BVD

• Current estimate is that about 10% of beef cow herds have at least 1 PI animal, and about 0.25 to 1% of calves born are PI.


• Veterinarians/Producers should have a surveillance strategy to determine level of herd risk for the presence of PI animals (High vs. Low Risk).


• Herds that are considered high risk for containing PI animals should utilize laboratory tests to do whole-herd screening to find all PI animals and then remove them.


• $10.00 to $24.00 per breeding animal (conservative estimate based on value of the cow and the lowered calf crop) a 200 head cow herd would lose $2000 to $4800 per year.



• In the feedlot economic impact can be tremendous.$21,000 to $100,000 have been lost in a few weeks by local feedlots.
  
  
  That’s all I’ve got to say for now!!!