CAUSES AND SYMPTOMS Pneumonia, chronic and acute, is a common disease amongst calves worldwide. It can have various causes, including a weak immune system due to poor colostrum intake, cold or poorly ventilated calf housing, milk being consumed too fast, and poor nutrition. Scientifically known as bovine respiratory disease, it results from a combination of viral and bacterial pathogens and problems with the calf’s immune system that are affected by external factors. Viruses usually start the process by damaging the lung, paving the way for bacterial infections to set in. Calves with pneumonia will have inflamed, damaged lung tissue and airways which negatively affects their lung function. Untreated, pneumonia will result in death, but even if the case is mild and the calf survives, pneumonia will raise the cost of production[1]. Heifers that were affected by pneumonia may have poor growth, fertility and milk production.
A calf with pneumonia can be spotted by observing their breathing rate – calves with pneumonia will be breathing noticeably very quickly. As well as this, they will have a high temperature (usually above 40ºC), crackly breathing and possibly be coughing with lots of nasal discharge, and lower food intake. However, note that a calf that is coughing but that does not display any of these other signs may just be in an area of poor ventilation, in which case you should move it and all other calves into a better-ventilated area with plenty of fresh air[2].
PREVENTION In order to prevent pneumonia, you must ensure that:
Calves receive at least 6 litres of colostrum within 12 hours of birth. This is to ensure that they have a strong immune system that can fight off the bacteria that cause pneumonia.
Calves are housed in an area that is well ventilated without being cold. In the M.A.R.S system, the tarpaulins can be used to control the temperature and ventilation within the pen. During the night and cold parts of the year the back tarpaulin should be lowered to keep the pen warm. The pen design means that there will still be good ventilation even with this tarpaulin lowered.
Feed calves with a good quality teat, such as a Milk Bar teat, that is in good condition and is not leaking. Feeding with a bucket or a poor quality teat/teat with a valve, will mean that calves drink their milk far too quickly, creating the possibility of milk flooding the lungs which can cause pneumonia.
Ensure that calves are fed sufficient volumes of milk until weaning, paired with fresh water, calf meal and hay at all times. See our blog on recommended calf feeding regime to check that you are feeding your calves properly. Well-fed calves will have a strong immune system and will be better able to fight off the pneumonia-causing bacteria.
Vaccinate! There are vaccines that can be given to calves to reduce the risk of getting pneumonia. These must be given along with a good management program.
TREATMENT If you diagnose a calf with pneumonia, action must be taken immediately as follows:
If you practise group rearing, remove the calf from the group and put her in her own pen.
Ensure the calf is drinking the correct volume of milk every day. Use a bottle to feed her if necessary.
Inject Hitet for 5 days once a day at 3.5 ml per 100kg calf weight.
Inject Ketosol for 3 days once a day at 1ml per 33kg calf weight.
If Hitet fails you may inject short-acting Penstrep for 3 days once a day at 1ml per 20kg calf weight.
[1] What Are the Causes of Calf Pneumonia and What to Do to Prevent It? agriland.ie 21/11/17 [2] Pneumonia in Dairy Calves, Fred Gingrich, Dairy Herd Management, 30/03/12.