Calf pneumonia is a multi-factorial disease that is very prevalent in housed calves, both dairy and beef, particularly between the ages of one to five months. Due to this it is difficult to manage and we have to use lots of different tactics to control and prevent outbreaks.
When an outbreak occurs it is best to pick things up early so that damage can be reduced to that individual as well as trying to reduce the risk to others. Early signs that may indicate a pneumonia problem include:
– Dullness, reduced feed intake, hollow looking, temperature above 39.5°C (a thermometer is very useful)
– Increased respiratory rate and a watery discharge from the nose and eyes
Monitor calves when they are resting for these early signs as it can be missed at feeding time. Later stages of disease can appear as one or more of purulent nasal discharge, coughing and severe respiratory distress which greatly reduce the likelihood of survival, if they do survive it is likely to leave chronic damage which will affect their productivity.
Several different antibiotics can be used in the treatment of pneumonia but these only work on the secondary bacteria, often viruses are the initial pathogen. Animals with obvious signs need treating quickly and in contact animals may require prophylactic antibiotics. Treatment may fail if the disease has progressed too far or if it is a serious viral outbreak. Therefore it can be beneficial to undertake some testing and find out what you are dealing with as well as consulting your health plan and/or vet for advice when working out a treatment plan.
An anti-inflammatory should always be given as this will help the antibiotic work as well as making the animal feel better and encourage it to eat so improving the outcome. Remember to consider lung worm if any animals have been grazed and the use of an appropriate anthelmintic if necessary.
Many of these infectious agents are present in normal healthy calves so we need to think about why certain farms or groups get outbreaks. If a calf has a weak immune system then they are more likely to suffer. This commonly could be related to a poor nutritional start, the presence of BVD, poor ventilation and housing or mixing with older stock.
Ensuring good nutrition from the beginning will promote a healthy immune system and may save you a lot of expense dealing with sick, unproductive calves in the long run. As a general rule feeding 3L of first milking colostrum within 1-2 hours of life followed by regular sufficient feeds of second colostrum, for at least 4 days will encourage growth and a healthy calf. Use of a colostrometer will allow you to feed good quality colostrum. Additionally, calves can be blood sampled at less than seven days of age to assess the adequacy of their colostrum intake.
Minimising scour outbreaks will help keep pneumonia levels down as both have similar risk factors and those with scour will have a suppressed immune system, making them more vulnerable. They should continue to receive milk feeds as well as electrolyte feeds because a negative energy balance will reduce their ability to fight off infection. This goes hand in hand with tackling BVD as it is a major contributor to weak immune systems and therefore disease outbreaks. Active BVD surveillance in conjunction with active health planning will help you to tackle this so speak to your vet if you don’t already have a plan in place.
Reducing stress is also incredibly important, most will know during times of stress is when you are more likely to succumb to that cold. Therefore bear in mind when doing things such as disbudding, consider pain relief or at least minimise other stresses, for example mixing calves in to different groups.
Good hygiene in calving pens and ensuring prompt removal of calves to appropriate housing is key to preventing infections when they are very vulnerable, always remember to treat navels. There are lots of different housing systems and no one system fits all, however the main thing to remember is good ventilation without causing draughts.
A few changes to a calf shed may greatly reduce pneumonia levels so it is always worth having a discussion with your vet. Keeping calves individually will generally make it easier to prevent pneumonia however any system that is well designed and maintained can be effective. If calves are kept in groups try not to change these groups as you may inadvertently be introducing disease as well as causing stress. Try to avoid adult animals sharing the same airspace as calves as many infectious agents are spread in the air.
Managing bought in calves can be even more of a challenge because we have been unable to control their start in life. Buy calves from as few sources as possible and try to find out what there management protocols are. Quarantining bought in stock for one month is ideal. Careful observation during this time along with monitoring rectal temperatures of “off colour” calves will help you to detect early stages of disease and deal with them most effectively. If possible when groups are introduced it would be ideal to do it after turnout so disease transmission is reduced.
Vaccination can be a useful tool but it should not be relied upon as no vaccine will be one hundred percent effective if there is still a huge challenge. Intranasal vaccines are available that provide protection quicker than intramuscular preparations, as long as the instructions for use and storage are followed appropriately.
The key points to remember are:
- – Early diagnosis and treatment as well as treating for long enough, for the best outcome
- – Prevention is better than cure so assess your system and focus on areas for improvement
- – Correcting and maintaining housing so there is plenty of fresh air but no draughts with plenty of dry bedding
- – Try not to mix groups of calves and in particular do not hold back the poor calf in to the younger group as it is very likely to spread disease
- – Avoid calves sharing air space with adults as this a big risk
- – If using vaccines follow the guidelines
- – Seek veterinary advice if appropriate
Source: Western Morning News