Spring-born suckler calves generally remain with their dams at pasture until they are weaned, usually between five and nine months of age. Weaning stress has an adverse effect on the immune system, making calves more susceptible to disease, particularly pneumonia.

It is essential for the health and performance of these calves to minimise stress around weaning by having good handling facilities and using proper weaning procedures.

Common causes and clinical signs of pneumonia in weanlings

Pneumonia in suckler-bred calves around the time of weaning involves a combination of infectious agents, together with poor management and husbandry factors, leading to a disease outbreak. The infectious agents that cause weanling pneumonia are a range of viruses and bacteria, and calves may be infected with more than one of these at a time.

The viruses that most commonly cause pneumonia are Bovine Herpesvirus 1 (BoHV1 – the virus that also causes Infectious Bovine Rhinotracheitis (IBR)), Bovine Respiratory Syncytial Virus (BRSV) and Parainfluenza Virus 3 (PI3V).

The bacteria involved include Mycoplasma bovis, Pasteurella multocida, Mannheimia haemolytica and Histophilus somni. Early diagnosis is essential for the successful treatment of pneumonia, together with good stockmanship and requiring calves to be observed on a regular basis post-weaning.

Initial signs of pneumonia can be non-specific and include being off form, dullness, reduced feed intake and lack of gut fill.

Other signs may include fever (over 39.5°C), increased respiratory rate, watery nasal discharge and severe breathing difficulties.

By the time these later signs are noted, the disease is advanced and treatment is less likely to be successful as damage to the lungs may be irreversible.

If you suspect weanling pneumonia, consult your veterinary practitioner for advice on diagnosis and treatment.

Pneumonia prevention

Pneumonia around the time of weaning has the potential to cause significant performance losses and even death in weanlings. The risk of pneumonia is increased by a series of factors, including poor weaning management, sheds with poor ventilation and additional stressful events around weaning, including mixing newly bought animals with homebred animals.

If you are buying weanlings, quarantine new animals after arrival, ideally outdoors or in well ventilated buildings for at least four weeks before mixing with homebred animals.

Vaccines are available against the most common viruses and bacteria that cause pneumonia.

Vaccines need time to build up protection and courses should be completed before the time of weaning and housing to have the best effect.

For most vaccines, this means beginning the vaccination programme at least six weeks before the planned date of weaning. In some situations, vaccination may also be used in the face of a viral respiratory disease outbreak.

Best practice in handling, administration and storage of vaccines

  • Always check with your vet prior to vaccine administration. Allow the vaccine to reach ambient temperature (15°C - 25°C).
  • Always read and understand the manufacturer’s instructions before use.
  • Record all vaccines given to animals e.g date, animal number, type of vaccine used in your own animal remedy records.
  • Never mix vaccines or administer within 14 days of each other unless the manufacturer’s instructions state otherwise.
  • Never use the same needle or syringe for different vaccines.
  • For vaccines given intra-nasally, the supplied applicators are designed to break up the vaccine into minute droplets, so it is important to use it to disperse vaccine in the nasal chambers.
  • If not vaccinating all animals, separate vaccinated groups from unvaccinated groups that need to remain free from viral antibody.
  • This is necessary to avoid possible spread of live vaccine virus from vaccinated animals, which may excrete virus for up to five days following intra-nasal vaccination.

    Separating these groups will avoid accidental contact with the vaccine virus, resulting in their becoming antibody positive. For some vaccines, e.g IBR, this would prevent their entry to a semen collection centre or bull testing station.

  • Read manufacturer instructions if mixing with other vaccines, as some product can’t be mixed with other vaccines.
  • Do not use with immunosuppressive products such as corticosteroids. If there is any doubt about other animal remedies, use on a case-by-case basis in consultation with your veterinary practitioner.
  • Always store vaccines in a fridge at 2°C - 8°C.
  • Always check the shelf-life of the product and never use expired vaccines. Once opened (seal broken), check the longevity of the product (usually hours).
  • Animal health tips

    Parasites control

    Lungworm (hoose) infection in adult cattle and calves can give rise to husky coughing depending on the grazing management and dosing regime carried out on-farm. Roundworms in youngstock will increase if animals are not dosed appropriately. Fly control is also important.


  • In preparation for the autumn, review vaccination protocols with your vet.
  • Give a broad-based Clostridial vaccine if there has been a past issue on the farm.
  • Mineral supplementation:

  • Copper, cobalt and selenium/vitamin E are the most important trace elements that affect performance.
  • Talk to your vet if you think mineral supplementation on your farm might need a review.
  • Milk recording

    Do at least one milk recording before drying off. These are important individual cow records for selective dry cow therapy this autumn.