SIR — During my long career as a country veterinary surgeon, nature taught me time and time again that if there is trouble with animals you have to find and eliminate the source.

If it is an infection then the species of bacteria, virus or mycosis needs to be treated adequately. If you fail to get rid of these sources of infection then sooner or later there will be more trouble and misery. It is exactly the same as toothache.

With tuberculosis an infected animal or herd is a focus. If you do not manage to eliminate that focus or if you do not even try to do it, the problem will get worse.

Vaccinating before the herd is clean will definitely aggravate the situation. Any treatment of infected animals is contraindicated, hence the slaughtering of all bovine TB reactors.

If politicians continue to ignore the advice of experienced veterinary surgeons about how to get rid of bovine TB, nature will hit back and teach them a lesson or two.

Nature does not look back, does not care how much money is spent, she just keeps going her own way.

Vast amounts are being spent on compensation and on future schemes. This money will be totally wasted unless the government is brave enough to accept the fact that huge reservoirs of bovine TB lie in the overcrowded badger population.

Some 40,000 head of cattle are being culled every year due to TB and this figure will be rising annually.

It is unclear how many tens of thousands of badgers are infected and are further spreading TB.

DEFRA seems to ignore or tries to vaccinate even diseased "brocks" and in some five to eight years time possibly all cattle with a dubious vaccine called BCG, which could well induce further spreading.

All these tools in DEFRA's box - as they use to call it - cannot be seen as any other action than a red herring.

Maybe the Government also needs to consider the welfare of the whole badger population. Death by TB is extremely slow, miserable and painful.

Finally, bovine TB can also be infectious to humans, cats, dogs and some domestic animals. People with TB are normally treated with heavy cures containing a combination of three different antibiotics over periods of six months or more – sometimes unsuccessfully.

Dr Ueli Zellweger,

Winsford.