Calf house conditions can cause pneumonia; VET'S VIEW.

Byline: IAIN CA RRINGTON

RESPIRATORY disease is caused by a complicated interaction between various infective agents, the environment and the immune status of the individual.

It has been calculated that the cost of a case of pneumonia can range between pounds 30 for mild cases to pounds 500 for the severe cases involving mortality. Now is the time to consider your strategy for prevention and vaccination.

The main thrust of pneumonia generally shows itself in the run up to Christmas sometimes stretching into the New Year and is related to housing.

Adult cattle are an important source of many of the infective agents. Although not showing symptoms of disease, they can be carriers releasing large amounts of these agents when they are stressed around calving or housing.

The common causes of pneumonia (Bovine Respiratory Disease - BRD) can be divided into two groups by their causative agent, bacterial and viral.

Often infections are mixed with agents from both groups acting together to cause the disease we all call pneumonia. The most common bacteria involved are Mannheimia (formerly Pasteuella) haemolytica, Pasteuella multocida, Histophilus somni (formerly Haemophilus somnus) and Mycoplasma species, especially M.bovis.

Of these disease agents a vaccine is only available for M. hamolytica. Treatment for these conditions is with appropriate antibiotics and anti-inflammatory products - your vet will be able to advise you.

Viral agents associated with BRD are more complicated as specific antiviral treatments are not available and antibiotics are only useful to control secondary bacterial infections. Anti-inflammatory agents are useful in reducing the damage to the lungs, but in the end the animal must fight the disease itself. The main viral diseases are RSV (Respiratory syncytial virus), IBR (Infectious bovine rhinotracheitis) and PI3 (Parainfluenza type 3). Vaccines are available for all these diseases.

Although vaccines are not available to stop all forms of BRD they should reduce the impact and make cases easier to deal with, except when a new disease agent arrives on the farm. In these circumstances rapid diagnosis is important to limit the spread of disease.

Damp and mild weather conditions appear to be a contributing factor in many outbreaks. Other factors contribute to these problems, such as poor ventilation of buildings, mixing of age groups in the same airspace and sub-optimal feeding. These factors need to be taken into account when considering the course of action to be taken. Many of the buildings which house calves have far from adequate ventilation. Ventilation is not a gale blowing through the calf house, but it should: 1. Remove excess water vapour (humidity). 2. Remove excess heat.

3. Remove micro-organisms, dust and gases. 4. Provide uniform distribution of air.

5. Supply six air changes an hour.

So the next time you enter the calf house or creep area take a look around. Are the cattle wet from condensation, are there cobwebs on the roof struts and does the atmosphere take your breath away? If so you should consider rapid and often drastic action. And always remember by the time calves are coughing, damage is already being caused, welfare compromised and profitability reduced.

Iain Carrington, Hexham-based Intake Vets