Bovine parainfluenza
This virus belongs to the genus Respirovirus in the subfamily Paramyxovirinae of family Paramyxoviridae. It causes respiratory syndrome in cattle and sheep affecting large number of animals especially in intensive breeding units. In young animals, the disease is marked by fever, lachrymation, serous nasal discharge, depression, dyspnoea and coughing. Affliction of the respiratory system by this virus predisposes to secondary bacterial invasion, especially by Pasteurella haemolytica. The disease is also known as 'shipping fever'.
Clinical signs: There is lacrimation, serous nasal discharge, depression, dyspnoea and coughing. The animals may recover in 3-4 days, or may develop secondary bacterial infection with purulent nasal discharge.
Diagnosis: The disease is diagnosed on the basis of clinical signs subject to the laboratory confirmation by haemagglutination inhibition, immuno- fluorescence and cell culture virus neutralization tests. Virus can be recovered from the nasal discharge for 7 to 9 days after infection and isolated in bovine cell cultures. For a sero-survey, paired serum samples are collected and processed for detecting antibodies. A 4-fold rise in antibody titre is suggestive of recent infection.
Prevention and control: Several attenuated virus vaccines are able to induce protective mucosal IgA antibodies. Combined vaccine containing infectious bovine rhinotrachitis, bovine adenovirus and bovine viral diahorrea have been used abroad