Cattle pneumonia is still the biggest economic and welfare cost in the Scottish livestock industry. It is most common in the first 12 months of life but can result in chronic disease and affect older cattle.

Pneumonia is a complex disease with lots of different causes and risk factors. The incidence varies greatly between holdings with some farms managing to achieve very low levels. It is possible to control pneumonia to a manageable level if the risk factors and different causes are understood. Respiratory disease in cattle is responsible for the greatest use of antibiotics, mortality and significant chronic disease, leading to poor growth rates, ultimately affecting value, fertility and potential milk yield.

Stress, immunity and environment are key to understanding pneumonia risk. With lots of different underlying causes, there is rarely one reason why an outbreak occurs.

Many of the infectious agents which cause pneumonia are already present or ‘endemic’ within livestock. Older cattle with immunity, carry viruses and bacteria without any symptoms at all. Many of these bacteria live at the back of the nose and throat in perfectly healthy animals.

Colostrum, from the day a calf is born can maximise immunity but, it must receive adequate quality and quantities. Antibodies within the colostrum protect the calf for several months of life, giving specific protection to pathogens within the herd.

Nutrition, adequate milk to maintain growth rates, especially in colder months is very important for dairy-bred calves. But also, calves receiving creep feed, without good quality forage can have ruminal acidosis, which can indirectly weaken their immunity.

There are some excellent pneumonia vaccines licensed in the UK and their use has transformed the level of disease on a lot of farms. But, because calf pneumonia can be so complex, vaccination must be used in conjunction with managing other risk factors, environment and stress. There is no ‘one size fits all’ when it comes to vaccination. Some vaccines are not licensed in calves under 12 weeks of age, many are two doses a month apart, some protect against singles agents and others can protect against both viruses and bacteria. It is very important when deciding what vaccine to use to work closely with your prescribing vet. Get the timing right, before the risk period on your unit. Vaccinate the whole group at risk, partial vaccination programmes are never as successful.

IBR risk

IBR is a herpes virus present on roughly half of farms, spread by carrier animals. It doesn’t directly cause pneumonia but causes serious inflammation and damage to the upper airways and windpipe. Unvaccinated, naive cattle of any age are at risk, uncontrolled disease can cause severe disease and potential mortality. It is often the cleanest cattle from the cleanest herds that are at the highest risk. If mixing cattle from different sources, vaccination again IBR should be considered. There are different ways to administer the vaccines but relatively cheap and cost effective.

With so many causes of pneumonia, it is unlikely that all stock can be protected, however, vaccinating against common causes may prevent an outbreak spreading through the whole group and vaccinated animals often respond to treatment more quickly, making the likelihood of whole group treatment much less likely.

Calf scours are also very common, and can weaken the animal's immunity and reduce growth rates resulting in greater susceptibility to pneumonia. BVD is thankfully much less common now in Scotland but still common south of the Border. BVD will profoundly affect calves' immunity if circulating within a group.

Read more: Farm buildings and how they can help prevent pneumonia in calves

Mixing animals of different ages and different herds is one of the biggest pneumonia risks. Home-bred animals may have stronger immunity to pathogens already on that farm. Buying cattle from different holdings, mixing through markets and then housing creates a perfect soup of stress, bugs and immune status to trigger serious outbreaks.

Automatic calf feeders are now popular on dairy systems. They can achieve good growth rates and are excellent at controlled weaning. These systems work best on an all-in all-out regime. Be careful mixing younger and older calves, as this can lead to cycle of contagious disease. Hygiene and individual calf care are essential.

Management procedures, weaning, castration and dehorning are all stressors which can be reduced or performed at other times of the year. Thankfully, more and more farms are managing these procedures much earlier when they have little impact on calf health.


Stocking density, over stocked sheds increases the chance of disease spreading through a group. Smaller batches of similar ages always work best.

Fresh air and ventilation, depending on age of animals maximise the stack effect, allowing warm stale air to escape from the roof, drawing clean, fresh air in to replace it. Consider active ventilation, using fans if the inlet in your shed isn't sufficient or the calves are too young for a stack effect to work.

Dry bedding – clean sheds out to reduce moisture and composting heat. Damp bedding retains moisture and heat, resulting in stale air, allowing viruses to survive longer, increasing risk of transmission.

Younger calves are also susceptible to cold, particularly dairy-bred calves so consider using calf jackets to protect at risk groups and create protected, draft free areas to keep calves warm.

By understanding the complex risk factors, immunity, stress and environment, the impact of pneumonia within a herd can be significantly be reduced. Work closely with your vet, have a health plan, discuss risk factors on your farm. Investigate outbreaks, use the excellent diagnostics available and consider vaccination as a cornerstone to prevention.