Causative agent 
-   BEF virus, family Rhabdoviridae

Differential diagnosis 
-   Infectious bovine rhinotracheitis
-   Parainfluenza-3
-   Respiratory syncytial virus infection
-   Bovine adenovirus infection

1. History taking 
-   Considerable loss occurs in dairy cattle due to
    depression of milk flow

2. Clinical examination 
-   Sudden fever, anorexia
-   Increased respiratory rate, dyspnea
-   Sharp fall of milk yield
-   Nasal and watery ocular discharge
-   Shivering and weakness of muscle
-   Limb stiffness and pain
-   Swelling at the shoulder, neck and back
-   Abortion (sometimes in the late stage of
    pregnancy)


3. Necropsy 
-   Inflammation of all serous surface
-   Swelling of lymph nodes
-   Congestion of abomasal mucosae
-   Pulmonary emphysema and bronchiolitis

4. Histopathological observation 
-   Congestion of abomasal mucosae and nasal
    cavities, small intestine and kidneys
-   Pulmonary emphysema and bronchiolitis
-   Degenerative changes in synovial membrane of
    joints with an increase synovial fluid

5. Hematology 
-   Leucopenia, neutrocytosis, lymphopenia


6. Serological test 
Specimen   : paired sera (2-3 week apart)
Method      : SN test


7. Virus isolation 
Specimen   : blood in anticoagulant (preferable
                    EDTA-blood)
Method      : suckling mice inoculation


8. Virus identification 
-   FA test
-   VN test


Control 
-   Modified live vaccine and inactivated vaccine