I had considered a different topic for this month but as often happens I have been overtaken by events. From Monday, April 9 routine periodic blood testing for Brucellosis will cease in beef herds.

It would appear that this is also true for dairy herds but due to the unseemly haste with which this policy has been introduced the information which we have finally been sent is unclear.

The reasons given for this decision are:

1. We are no longer required to do so under EU rules;

2. The tests add little to our ability to detect disease. Other mechanisms will do this;

3. It is not cost effective.

The reasons are understandable, if in some cases based on a false sense of security relating to the other systems now in place to identify and stop the possible spread of disease. Also this will mean any other surveillance carried out on these blood samples (Enzootic Bovine Leucosis and Warble fly) will cease. Concerns have also been expressed that this change in policy will reduce the number of farm animal vets available in practice, thereby compromising the ability to react to any disease outbreaks that may threaten us in the future.

The mechanisms that will now act to defend us are those that have been in place alongside testing - import controls and certification, post import checks and testing, routine monthly bulk milk tank testing in dairy herds and abortion reporting and investigation.

As every cattle farmer and farm animal vet can tell you, complacency relating to the reporting of abortions and their testing for brucellosis is widespread.

As this is now going to be a mainstay of our defence it is essential that the investigation of all cows that abort or calve less than 271 days after insemination or service is carried out for brucellosis (except in milking dairy animals).

It is a legal requirement to inform your local Animal Health Divisional Office (AHDO) of any such incidents, although you will probably do this through your own vet who can then carry out any testing required under the instruction of the AHDO. The samples taken for testing are usually clotted blood, milk and a vaginal swab but further samples from the cleansing or the foetus can be sent. It is possible to take further samples which can be sent for examination for other pathogens that are associated with abortion but these will be charged for by the laboratory.

Brucellosis (also known as Contagious Abortion or Bang's disease) is a disease of major economic importance worldwide. It is caused by infection with the bacteria Brucella abortus, and is characterised by abortion after the fifth month of pregnancy. In susceptible herds "abortion storms" can occur. Disease is followed by high levels of infertility and chronic infection is common, although cows only normally abort once, they spread the organism at subsequent calvings. Bulls can also be infected, causing an inflammation of one or both testicles. Spread is by direct contact with the organism. This is a zoonotic disease affecting man as well as animals and giving rise to "undulant fever" which produces "flu like" symptoms. The condition can be acute or a more chronic generalised condition. The disease is spread by contact or consumption of infected milk. Pasteurisation destroys the organism.

* Iain Carrington is with Intake vets, Hexham.