Calf pneumonia is of huge financial significance, costing the UK cattle industry millions of pounds annually. Dawn Prime gets expert advice on prevention and treatment.
Losses caused by pneumonia in calves arise from cost of the treatment, reduced weight gain and increased labour.
Unfortunately this disease is multifactorial, which means viruses, bacteria, husbandry and management factors all have an impact on an outbreak.
Calf pneumonia is a common disease in the dairy and beef industry, and a dominant pathology seen on any post-mortem performed on calves which are under six months of age.
Alun Beckett, a vet at the Lancashire branch of Lambert Leonard and May, explains that while mortality rates caused by calf pneumonia can be quite low, at less than 5 per cent, a case of pneumonia can lead to an increased risk of morbidity.
Mr Beckett says: “Other than death, the biggest issue is the decrease in the average daily liveweight gain and subsequent productivity.
“When calf pneumonia affects a dairy system, it can result in the heifers taking much longer to get to the correct service weight, which results in the heifers calving down older than the target of two years of age.
“In a suckler herd, it can take longer for the animal to finish and if the damage to the lungs is significant then they may never reach their true potential.
“And the continual use of intramuscular injections to treat the pneumonia can have a negative impact on the carcase quality, and in turn the subsequent value.”
Prevention is always better than cure and Mr Beckett says there are many steps that can be taken to decrease the risk of infections and the transmission of pneumonia.
“The environment is a major factor and has a direct impact on the probability that a calf will contract pneumonia,” he adds.
To help prevent incidences of pneumonia, Mr Beckett emphasises the importance of good colostrum management, with colostrum providing an instant energy source and essential antibodies.
“These antibodies will give the calf protection during the first few weeks of its life,” he says. “If the calf does not receive the adequate amount of good quality colostrum within the first six hours of its life, it can increase the calves chances of contracting pneumonia and other diseases.”
He also says diseases such as BVD can immunosuppress a calf’s immune system, meaning it can havea huge impact on the calf’s ability to fight other diseases. It is important to know the herd’s BVD status and set up a control programme if BVD is present.
Identification and treatment
THE prompt identification, treatment and isolation of any animals exhibiting the clinical signs of disease is another important step. These sick calves will act as a reservoir of infection, exposing its entire group to an increased level of risk.
A good vaccination protocol is vital to protect any herd and to use vaccines that target the correct agents. These are herd specific, and should be vaccinated at risk periods like housing.
A vaccination programme can have a positive impact on the welfare of the herd and can improve profits for the farm. The cost of the vaccines depends on the protocol which has been discussed with your veterinary surgeon.
There are many treatment protocols for pneumonia, but it is really important that all farmers seek veterinary advice prior to starting any treatment.
Some of the most common causes of pneumonia are viral pathogens, which antibiotics are unable to treat.
Antibiotics are used to treat the secondary bacterial infection that could have been caused by an opportunistic pathogen.
Some causes of pneumonia can be caused by the species of Mycoplasma, but unfortunately not all antibiotics can be effective at treating this pathogen.
To get full value for money on any antibiotics, it is essential that an appropriate class of drug is used and for the correct amount of time - your veterinary surgeon will discuss the treatment protocol with you.
Furthermore, giving only half a dose or shortening the time of treatment, will lead to resistance to that antibiotic, while still leaving the calves unwell.
Another decision that can have big financial implications is if you should treat an individual calf or the entire group.
The cost will increase with the more calves that are treated.
However, the financial loss from pneumonia could be greater than the outlay for treating the whole group.
Anti-inflammatories should be used alongside antibiotics and are arguably the most important for long-term success.
These are important in reducing inflammation within the lung which limits long-term damage and help to reduce the fever, resulting in the calf feeling better sooner and minimising financial loss.
Ventilation is a key priority to help reduce the transmission of the cause, be they viral or bacterial. Warm, moist air is often held responsible for the increase in calf pneumonia, however these cases often occur when the housing is not ventilating correctly via the stack effect.
■ Having different ages of calves from multiple sources, or calves and adult cattle housed in the same airspace, will increase the risk of pneumonia. It is ideal to house the animals in small groups of the same age. If this is not possible then the building should be organised so that the fresh air is drawn into the building so it passes over the youngest calves first.
■ A build-up of manure can increase the risk of pneumonia, as this can lead to an increase in levels of ammonia within the building’s airspace. Ammonia can weaken a calf’s defence mechanisms and cause damage to the mucosal lining of the respiratory tract.