Pneumonia in Dairy Calves
What is pneumonia?
Pneumonia is a disease of the respiratory system that can cause reductions in performance and growth. It s occurrence and severity is directly related to the environment the calves are kept in.
Pneumonia can be caused by a variety of bacteria, viruses and mycoplasms.
Housing contributes greatly to the development of pneumonia in a group of calves. The following all contribute to an increased risk of pneumonia in a group of calves :-
• High humidity due to damp bedding
• Poor air movement
• Inadequate levels of colostrum feeding
• High levels of atmospheric ammonia ( as a result of damp bedding and poor ventilation)
Coughing, increased breathing rate and effort, increased rectal temperature (103F (39.4C) and above).
There are very few farms that don’t experience pneumonia in their calves to some degree. Even if clinically sick animals are not seen there may be subclinical infection (infected but no outward signs of pneumonia). Occasional coughing in a group of calves is to be expected but if the majority of the group cough when they are active e.g. at feeding time or after being handled, then you should investigate further. Taking a rectal temperature of all the calves in a group can indicate currently infected animals (temperatures of 103F (39.4C) and above are suspicious)
Remember, one or two coughing calves may just be the tip of the iceberg and many more calves in the group may be infected subclinically (but still developing lung damage).
It is important to plan to reduce the risk of pneumonia even if you don’t feel you have had a problem during the last few y
Infected animals may develop damaged lung tissue which restricts their growth and not reach production targets in later life. They may also be more prone to other diseases. Calves often die or are culled in cases of severe disease.
The main costs are seen:-
1. In losses of calves that die or need to be culled
2. In the cost of drugs used to treat infected animals
3. In labour and time costs spent treating infected animals
4. Later in life as lower than expected production from animals with lung damage from a case of pneumonia as a calf.
A lot of time and effort is put into heifer rearing so prevention of pneumonia and its effects should be a priority.
Generally clinical signs (coughing, rapid breathing and raised rectal temperature) are enough to diagnose a problem. Further tests can be carried out to identify the actual causative organism if your vet feels this is appropriate to the control of the disease on your farm.
Antibiotics and anti-inflammatories are equally important in the treatment of pneumonia.
Antibiotics are used to treat some causative bacteria (they are not effective against viruses) and to protect against secondary bacterial infection of the already damaged lung tissue.
Anti-inflammatories help reduce the damage that is caused to the lung as well as helping to reduce the calves rectal temperature – this will make them feel better and help them to continue feeding and stay hydrated. Anti-inflammatories help to prevent the longer lasting effects of pneumonia on the calf i.e. production losses etc.
If caught early pneumonia can be successfully treated. More advanced cases have a less favourable prognosis.
The good news is that with a little attention to the housing and husbandry of the calves, the incidence of pneumonia in subsequent years can be greatly reduced.
Preventing pneumonia is far better than curing the condition. You need to concentrate on 3 areas to fully get control of the disease.
1. Housing – Assess and correct any issues such as ventilation, draughts, leaks etc in the sheds. Use smoke canisters to assess airflow in fully stocked calf houses.
2. Husbandry – Assess and correct any issues regarding stocking density, bedding, air quality, grouping of calves and colostrum feeding.
3. Protection – Discuss with your vet whether a vaccination protocol would be useful to help prevent pneumonia amongst your calves. Vaccination alone may not be able to prevent pneumonia but along with husbandry changes vaccination will reduce the severity of disease and the subsequent damage caused to the calves.
4. Treatment - Discuss treatment options with your vet. Early identification of clinical cases is essential. Remember anti-inflammatories and antibiotics are both important.
5. Isolation – Isolating clinical cases in a separate air space to the rest of the group will reduce the spread of disease – again early identification of clinical cases is important.