Bovine respiratory syncytial virus (BRSV)

Bovine respiratory syncytial virus (BRSV) is a negative-sense, single-stranded RNA pneumovirus closely related to human respiratory syncytial virus (RSV). It is a major cause of respiratory disease in cattle, particularly young calves, and a leading contributor to the bovine respiratory disease (BRD) complex, which causes substantial economic losses in both beef and dairy production.[1][2] BRSV replicates primarily in ciliated respiratory epithelial cells and type II pneumocytes, inducing a strong pro-inflammatory immune response characterized by recruitment of neutrophils, macrophages, and lymphocytes to the respiratory tract.[3] The virus causes significant immunosuppression that increases susceptibility to secondary bacterial infections, with *Pasteurella multocida* being the most common secondary pathogen; approximately 90% of BRSV infections result in secondary bacterial pneumonia.[1] While commercial vaccines are available, BRSV presents a therapeutic challenge due to its high mutation rate and antigenic variation across four subgroups, making complete immune protection difficult.[1] Treatment is primarily supportive, involving NSAIDs for inflammation reduction and antimicrobials for secondary infections, as specific antiviral therapies are limited.[1]

Other names

Bovine respiratory syncytial virus (full name)BRSV (abbreviation)Component of bovine respiratory disease complex

Vaccines provide immunological protection; live attenuated virus vaccine candidates have been developed. NSAIDs reduce fever and inflammation. Antimicrobials combat secondary bacterial infections. Supportive care involves fluid therapy, electrolytes, and nutritional support.