Bovine Parainfluenzavirus-3 (BPIV-3) is a member of the family paramyxoviridae and was first isolated from cattle with shipping fever in the USA. Its virulence varies with isolates (or subtypes). Alone, this virus does usually only produce mild to subclinical infections in cattle, but its most important role is to serve as an initiator that can lead to the development of secondary viral or bacterial diseases, such as Bovine Respiratory Syncytial Virus or Infectious Bovine Rhinotracheitis.
Occurence of the disease in cattle is usually thought to be due to stress as a result of mixing of animals of different age groups, transport and winter housing. Poor hygiene may also contribute to an infection of Bovine Parainfluenza virus-3.
Symptoms and signs include fever, cough, serous nasal and eye discharge, increased respiratory rate and increased breath sounds. The severity of symptoms worsens with the onset of bacterial pneumonia. Fatalities from uncomplicated Bovine Parainfluenza virus-3 pneumonia remain rare.
. The virus can be replicated in cells in vitro, including calf, goat, buffalo and camel, suggesting that Bovine Parainfluenza virus-3 (BPIV-3) can infect these species too. A vaccine is available and is sometimes used to protect humans.
The problem with Bovine Parainfluenza virus-3 is that, like Influenza viruses, the virus is prone to mutations. Research has demonstrated that there were already two distinct BPIV-3 genotypes (BPIV-3a and BPIV-3b) circulating. A third genotype has recently been discovered and was tentatively classified as BPIV-3c.
These genotypes may also impact on BPIV-3 vaccine formulations. Furthermore Bovine Parainfluenza virus-3 (BPIV-3) and Human Parainfluenzavirus-3 (HPIV-3) may recombine to become a new and potentially highly pathogenic virus. And did I already mention the closely related Murine Parainfluenza virus-1?
 Klippmark et al: Antigenic variation of human and bovine parainfluenza virus type 3 strains in Journal of General Virology - 1990
 Horwood et al: Identification of two distinct bovine parainfluenza virus type 3 genotypes in Journal of General Virology - 2008
 Oem et al: Molecular characterization of a Korean bovine parainfluenza virus type 3 isolate in Veterinary Biology - 2013