Calf pneumonia

Calf pneumonia is a major problem in dairy and beef herds. It is a multifactorial disease and the most common post-mortem diagnosis in calves between one to five months of age.

Infectious agents involved include Mannheimia haemolytica, Haemophilus Somnus, Infectious Bovine Rhinotracheitis (IBR), bovine Respiratory Syncytial Virus (RSV), and Parainfluenza III Virus (PI3), along with many other bacteria and mycoplasma species and viruses.

Environmental factors include low environmental temperatures and high humidity and poor ventilation and also direct draughts onto calves themselves. The relationship between season and outbreaks may also be related to management practices including calving patterns and mixing of different ages of calves.
There are two types of the disease, acute and chronic.


  • Dull and depressed
  • High temperature
  • Raised breathing due to lung damage
  • Nasal discharge
  • Coughing
  • Reduced food intake
  • Chronic pneumonia is more gradual in onset with no distinct ill phase and the cow may appear to still eat well but may have a slight nasal discharge, sometimes with an increased respiratory rate and cough. Both forms of respiratory disease cause production losses as there is a reduction in live weight gain and there may be deaths in the acute syndrome.