− | A pneumonic disease which is principally of viral origin although mycoplasmas have also been implemented, which are mildly pathogenic unless secondary bacterial infection occurs. In calves a number of infectious agents are involved in the disease. These include [[Bovine Respiratory Syncytial Virus|Bovine respiratory syncytial virus (BRSV)]] - can be primary, causes suppression of pulmonary immune response | + | A pneumonic disease which is principally of viral origin although mycoplasmas have also been implemented, which are mildly pathogenic unless secondary bacterial infection occurs. In calves a number of infectious agents are involved in the disease. These include [[Bovine Respiratory Syncytial Virus|Bovine respiratory syncytial virus (BRSV)]], [[Bovine Parainfluenza - 3|Parainfluenza- 3 (PI3)]], [[Flaviviridae|Bovine viral diarrhoea virus (BVDV)]], [[Adenoviridae|Adenoviruses]], [[Coronaviridae|Calf coronavirus]], [[Infectious Bovine Rhinotracheitis|Bovine herpes viruses]]. [[Mannheimia haemolytica|''Manheimia (Pasteurella) haemolytica'' serotype A1]],[[Pasteurella multocida|''Pasteurella multocida'']], [[Arcanobacter pyogenes|''Arcanobacter pyogenes'']] and ''[[Haemophilus somnus]]''. |