The annual economic impact of bovine viral diarrhea (BVD), an immune-suppressing virus that leads to secondary infections from other pathogens, is estimated to cost the U.S. cattle industry about $3 billion/year. And, it's estimated that BVD incidence is increasing 10-15% annually.

Novartis Animal Vaccines, Inc., has the newest tool in that battle. Arsenal 4.1 is a four-way, modified-live vaccine for use in open beef and dairy cattle. It's designed to help prevent BVD Types 1 and 2, including the non-cytopathic (NCP) Type 1b strain.

BVD is somewhat misnamed, as diarrhea isn't often seen in affected animals. The main effects are associated with respiratory disease in feeder animals and reproductive disease in pregnant cows, though sudden death in cattle of all ages has been seen.

BVD can cause in utero infections that result in permanently infected (PI) fetuses. When born, these animals shed large numbers of the virus and are often the primary source of BVD disease in beef herds. Thus, exposure to infected animals from outside the herd isn't required.

There are hundreds of BVD strains, which fall into two broad genotypes — Type 1 and Type 2. Within Type 1, there are at least two subtypes — Type 1a and Type 1b. According to researchers, Type 1b appears to be the predominant subtype.

BVD viral strains are further classified by their biotype. A cytopathic (CP) virus causes cell pathology, while non-cytopathic (NCP) viruses show no pathology of tissue culture cells. Both CP and NCP biotypes can occur in BVD Type 1a, Type 1b and Type 2. NCP is the more damaging variation and NCP BVD has been found to be the major isolate in clinical BVD, accounting for 90-95% of all clinical outbreaks. The NCP biotype is also believed to be the cause of all BVD PI animals and is the major cause of BVD-induced abortions.

But, most leading BVD vaccines don't contain the NCP biotype or the Type 1b subtype, Novartis says. Arsenal 4.1 help protect against NCP Type 1b, in addition to Type 2, infectious bovine rhinotracheitis (IBR), parainfluenza Type 3 (PI3) and bovine respiratory syncytial virus (BRSV).

Arsenal 4.1 should be administered in a single, 2-ml dose, with revaccination annually or as recommended by a veterinarian. It's available in 10- and 50-ml-dose bottles and carries a subcutaneous-only label.

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