(BRD) Bovine Respiratory Disease

BRD is a problem commonly encountered by most farmers at one stage or another. A number of viruses and bacteria are implicated in outbreaks of BRD including;

  • Infectious Bovine Rhinotracheitis (IBR: Virus)
  • Bovine Respiratory Syncitial Virus (BRSV)
  • Parainfluenza Virus 3 (P13)
  • Bovine Viral Diarrhoea Virus (BVD)
  • Pasturella Multocida (Bacterial)
  • Manheimia Haemolytica (Bacterial)
  • Mycoplasma Bovis (Bacterial)

     

However BRD is not as simple as a pathogen causing disease, rather there is a complex interaction between the animals' immune system, the environment in which the animal is kept and one or more of the above bugs. BRD can occur at any time of the year, but is most common over the winter months, and is far more common in housed cattle although it can occur in animals at grass.

Clinical signs

CowsBRD is commonly a group problem of housed calves in a shared airspace, i.e calves in the same shed or byre. BRD can get into the herd in a number of ways. It can be brought in via animals bought at market, by animals moved from one farm to another, and can be brought on by stress i.e. sudden change in the weather, transport etc. It can affect all animals in the herd, but usually 50-75% of animals have visible clinical signs.

Clinically affected calves are usually dull, depressed and off feed with snotty noses, runny eyes and coughing either at rest or on movement. They often have increased temperature, and exhibit a faster breathing rate with increased effort to breathe. Occasionally obvious noises are audible as the animal is breathing. Clinically affected animals are the tip of the iceberg. It is likely all animals in the same shed will be affected to a greater or lesser extent. Therefore even though an animal is showing no signs of infection, lung damage is likely to have occurred and will result in a decreased rate of weight gain for that animal. This will lead to increased feed costs and loss in profitability for the farm.

Treatment

Treatment depends on the type of agent involved in BRD. However studies have shown the the use of a NSAID (Non Steroidal Anti Inflammatory Drug) such as Metacam along with an antibiotic can decrease the amount of lung damage that develops compared to treatment with antibiotics alone. Some drugs such as Nuflor, Resflor and Hexasol LA contain both an antibiotic and a NSAID in the one injection.

Prevention

Prevention is better than cure! A number of simple management procedures can drastically reduce the chances of BRD developing. Firstly good calf management is vital to ensure that the calves immunity is as strong as possible. Colostrum is vital and ideally all calves should drink 4 litres of colostrum within their first six hours. After this time the ability of the calves gut to absorb protective antibodies from the milk starts to decrease rapidly. Environment is key to decreasing the incidence of disease. Ideally all calves should enter the air space at the same time and no more additions should be made (this is not always possible especially on dairy farms). All calves should leave the airspace at the same time, and the pens should be thoroughly disinfected. Calves in the same airspace should all be of a similar age, and mixing of old and young stock in the same shed should be avoided.

Ventilation is also an important factor in BRD and must be considered at all stages of calf development. After the first few hours of life, a calf is unlikely to be too cold and the more ventilation present the better. The larger the airspace that the calves are kept in the less respiratory pathogens will be present per m³, and this decreases the likelihood of them picking them up. Ventilation is something that needs to be considered, especially in old outbuildings that have been converted to store young stock.

 

There are also a number of commercially available vaccinations all of which offer protection to one or more of the commonly encountered respiratory pathogens. These vaccines include:

  • Bovilis Bovipast RSP (Intervet)
  • Bovilis IBR Live (Intervet)
  • Bovilis IBR-Marker Live
  • Rispoval 3
  • Rispoval 4
  • Rispoval IBR-Marker Inactivated
  • Rispoval IBR-Marker Live
  • Rispoval Pasteurella
  • Rispoval RS
  • Rispoval RS & P13 Intranasal
  • Tracherine

     

For advice on choosing the correct vaccine for your farm, please contact us.