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Bovine Respiratory Syncytial Virus (BRSV)

Bovine Respiratory Syncytial Virus (BRSV)

BRSV was named for its characteristic cytopathic effect, the formation in infected tissue of syncytial cells, giant multinuclear cells formed by the fusion of several cells. BRSV has a predilection for the lower respiratory tract, where it can cause varying degrees of pneumonia by itself. Secondary bacterial infections, frequently involving Mannheimia (Pasteurella) haemolytica, causes disease of greater severity or death. Transmission is via respiratory aerosols or from direct contact with infected cattle.

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  • BRSV infects the mucosal cells lining the respiratory tract, destroying the mucociliary apparatus that clears pathogens and particulate matter from the airways. This process leaves the underlying tissue vulnerable to viral infection and secondary bacterial infection.

  • Initial exposure to BRSV can produce acute respiratory disease, with subsequent exposure typically resulting in mild or subclinical disease. The spectrum of clinical signs in susceptible cattle can range from mild to life-threatening. A biphasic pattern has been described, where initial mild disease is followed by a severe and sometimes fatal episode. Clinical disease from uncomplicated BRSV tends to favor young, previously unexposed cattle, although mature animals can be clinically or subclinically infected. Clinical infection produces high fever, increased respiratory rate, spontaneous coughing, and nasal discharge. Most cases recover naturally.

  • Diagnosis may be made on clinical signs typical of viral respiratory disease, including fever, depression, inappetance, nasal discharge, spontaneous coughing, and increased respiratory rate.  

  • There is no specific anti-BRSV therapy.  Treatment is limited to antibacterial therapy for secondary bacterial infections and supportive treatment.

  • Vaccination with INFORCE™ 3, Bovi-Shield® BRSV, Bovi-Shield GOLD® 4, Bovi-Shield GOLD® 5, Bovi-Shield GOLD FP® 5 L5 HB, Bovi-Shield GOLD FP® 5 VL5 HB, Bovi-Shield GOLD FP® 5, Bovi-Shield GOLD FP® 5 L5, Bovi-Shield GOLD FP® 5 VL5, CattleMaster® 4+VL5, CattleMaster® GOLD FP® 5, CattleMaster® GOLD FP® 5 L5, or PregGuard GOLD FP® 10 may prevent, help prevent, control, or lessen the severity of the disease.