As part of my job, I work with Infectious Diseases (mainly sexually transmitted ones - HIV, Hepatitis, Syphilis, etc. :crazy
and I subscribe to an emerging infectious disease listserv. Here is the first comment I have seen on the listserv about the cattle deaths (BBM):
[Infectious bovine rhinotracheitis (IBR) is a highly contagious, infectious
disease that is caused by bovine herpesvirus-1 (BHV-1). In addition to
causing respiratory disease, this virus can cause conjunctivitis,
abortions, encephalitis, and generalized systemic infections. IBR was
originally recognized during the early 1950s in feeder cattle in the
western United States. The IBR virus can persist in clinically recovered
animals for years. The virus remains inactive until the animal is placed
under stress. The virus is shed in secretions from the eye nose and
reproductive organs. The clinical diseases caused by the virus can be
grouped into: 1) respiratory tract infections 2) eye infections 3)
abortions 4) genital infections 5) brain infections 6) generalized
infections of newborn calves.
Bovine viral diarrhea (BVD) is a viral disease of cattle and other
ruminants that is caused by the bovine viral diarrhea virus (BVDV). BVDV is
a member of the pestivirus genus. There are 4 recognized species within the
pestivirus genus.
The clinical signs of BVDV are highly variable, including a spectrum from
few to no signs to very severe signs that kill the animal. The signs can be
determined by the genotype of the virus, whether the infection was recently
acquired (that is, acute) or has been acquired for months (that is,
chronic), whether the animal is pregnant, as well as other factors. Some of
the signs of acute infection are fever, lethargy, loss of appetite, ocular
discharge, nasal discharge, oral lesions, diarrhea, and decreasing milk
production. Chronic infection may lead to signs of mucosal disease.
These 2 diseases are often in a complex called mucosal diseases. These
diseases seem to have more impact in cold weather.
There is not enough information in this article to speculate beyond this.
We hope a definitive report will be available soon.
Portions of this comment have been extracted from
<http://www.aphis.usda.gov/animal_health/emergingissues/downloads/bvdinfosheet.pdf>
and
<http://www.ansci.wisc.edu/jjp1/ansci_repro/lab/diseases_2002/IBR.html>