Over two million¹ calves in Ireland every year, but unfortunately far too many fail to reach adulthood because of disease. The incidence rate of bovine respiratory disease (BRD) or calf pneumonia, as it is more commonly known, is approximately 20%².

Calf pneumonia is the greatest single cause of morbidity and mortality in cattle in Ireland; responsible for 32% of deaths in this age group³.

Hence, it is a cause of major economic loss for the cattle industry. At a farm level, these costs are in the region of €49/dairy calf and €93/suckler calf4.       

So what makes up these costs?

Surprisingly, only 40% is represented by vets’ fees and medicines; the remaining 60% results primarily from mortality, reduced growth rates and reduced lifetime performance.

The facts:
  • The cost of non-fatal production losses to the EU cattle industry is €576 million5;
  • Calf pneumonia is the biggest known cause of mortality in calves aged between one month and one-year-of-age and is a major contributor to the losses that see an average of 14.5% of live born dairy heifers failing to reach their first lactation6;
  • Daily liveweight gains, targeted at 0.8kg/day, can drop as low as 0.4kg/day after an episode of respiratory disease5;
  • This growth check increases production costs and can directly result in a reduction in lifetime productivity.


Merial Animal Health is conducting an Ireland-wide survey to investigate calf pneumonia control practices on cattle farms.

Please take a few minutes to complete the survey and be in with a chance to win a Cosy Calf jacket. Click here to complete the survey

Causes of calf pneumonia

Calf pneumonia results from a complex interaction between disease-causing viruses and bacteria and the animal’s immune system that can be influenced by external stress factors.

The important viral causes of respiratory disease are bovine respiratory syncytial virus (BRSV), parainfluenza-3 virus (PI-3) and infectious bovine rhinotracheitis (IBR).

Bovine viral diarrhoea virus (BVDV) may also be associated with pneumonia in some herds due to the negative effects it has on an animal’s immune status.

These viruses can cause disease by themselves or damage the defence mechanisms of the respiratory tract and predispose to secondary bacterial infections of the lungs.

There are a large number of bacteria that can cause disease in their own right or act as secondary invaders following viral damage to the lung defence mechanisms.


The important bacteria associated with calf pneumonia are: mannheimia haemolytica; pasteurella multocida; histophilus somni; and mycoplasma bovis.

An animal’s susceptibility to calf pneumonia will be influenced by the strength of its immune system. In young calves, the single biggest factor affecting the immune system is colostrum.

Ensuring calves receive good quality colostrum as quickly as possible after birth will give them the best possible start in life and help reduce the risk of disease.

A calf’s immunity will also be affected by nutrition, management practices, stress and the environment – with issues in any of these areas having a negative impact on the calf’s ability to fight disease.

Mixing animals of different ages or from different sources within the same airspace will increase the risk of respiratory disease.

Similarly, if animals are placed in sheds that are poorly ventilated or humid, even high levels of immunity will not prevent disease outbreaks. Click here to win a calf jacket


Given the multi-factorial nature of the disease, good calf pneumonia control programmes rely on implementing an appropriate vaccine strategy, alongside improvements to management practices, to reduce the risk of disease.

Vaccines are available that will enhance protection against the common viral and some of the bacterial causes of calf pneumonia.

It is important that vaccines are administered prior to high risk periods to ensure that there is sufficient time for animals to develop effective immunity.


#CALFMATTERS is a vaccination campaign from Merial Animal Health, which supports our veterinary customers in encouraging farmers that have not vaccinated against calf pneumonia to vaccinate their calves by reducing the overall cost of vaccination.

The aim of this survey is to collate information on: calf pneumonia incidence across the UK and Ireland; attitudes to calf health, specifically respiratory disease and attitudes to disease, prevention and management, including vaccination, treatment of respiratory diseases (antibiotic use) and current practice on preventing calf diseases.


  1. Irish Department of Agriculture, Food and the Marine (2016) AIM Bovine Statistics Report 2016;
  2. Atkinson, 0. (2016) Welsh Dairy Heifer Report. Hybu Cig Cymru;
  3. All Island Disease Report 2015, AFBI/DAFM Veterinary Laboratories;
  4. Andrews AH (2000) Calf Pneumonia Costs! Cattle Practice 8(2);
  5. Stipkovits L., Rosengarten R., & Frey L. (1999) Mycoplasmas of ruminants: pathogenicity, diagnostics, epidemiology and molecular genetics, Edition: Volume 3, Chapter: Impact of mycoplasma infections on respiratory disease in cattle in Europe, Publisher: European Cooperation on Scientific and Technical Research, 18-32;
  6. Brickell, et al. (2009) Mortality in HF calves and replacement heifers in relation to bodyweight and IGF-1 concentration on 19 farms in England. Animal 3(8) 1175-1182.