SIR — The darkness and sticky air conditions in a badger set is the ideal climate for tuberculosis bacteria to survive for months.

Any cub born in a set with Tb is likely to get infected in the first few weeks of his shortened and possibly very miserable life. It might be even infected by its own mother.

Some will die soon and some will be carrying this Tb infection in latent form until they die.

If such an already infected badger is vaccinated with BCG, there is the risk that the latent infection opens up with the consequence that this badger is spreading billions of TB bacteria.

Where is the animal welfare aspect?

Unlike most other common vaccines, the BCG vaccine does not stimulate the huge production of specific antibodies.

Thus the BCG vaccine does not prevent an infection - the only thing it does is reduce the risk of a so-called bacteriaemia, which means that the risk of Tb bacteria being spread via the blood or lymph-flow is reduced (but not eliminated ).

It is highly unlikely that the European Veterinary Commission will ever accept that England uses the BCG vaccine for cattle. Why should it expose all other European countries which have managed to eradicate bovine Tb to the risk of reinfection?

Much more likely is, sooner than later, a total import ban of any English livestock, dairy and beef products.

Bovine Tb is a matter to be sorted out by veterinary science and not by laymen like politicians and musicians.

It is obvious that in this country the way to deal with this very long-known disease has utterly failed over the last ten or 15 years.

There are highly experienced and well -respected senior veterinary epidemiologists in Europe. Why not ask one or two of those for advice on what to do? It should have happened ten or more years ago.

Finally, I am amazed that in all the discussions about bovine Tb, the testing of dairy and beef herds and biosecurity on farmyards, the role of pet cats is never mentioned.

Cats can carry it and, being a veterinary surgeon myself, I remember very well one single cat in my home country some 35 years ago which infected and re-infected three different dairy herds in one bigger hamlet over almost two years.

To diagnose Tb in a cat the usual intra-dermal test is not reliable. The only way to do it is by radiography or by long lasting cultures of dubious excretions.

Dr Ueli Zellweger,

Winsford.