Mark Purdey, an organic farmer of Elworthy, Somerset, asked for the animal to be put down on Tuesday after its condition had deteriorated. A post mortem examination will now be carried out to establish the cause of Damson's illness.
A week ago Mr Purdey's own vet, Mandy Fraser, injected Damson with oxime, a chemical carried by troops in the Gulf war as an antidote to nerve gas. Within 90 minutes the cow, which had been showing all the disoriented symptoms of BSE, appeared to have made a remarkable recovery.
Mr Purdey believed that visible success of his radical prescription suggested that BSE might be caused by organo-phosphates, chemicals used to combat warble fly in cow hides, and not by contaminated feeds as the Government says.
Last Friday Miss Fraser's senior colleague, Christopher Budge, took over the case and examined Damson in the presence of John Cohen, a government vet.
Over the weekend Damson's condition deteriorated and Mr Purdey asked his vet to continue the oxime injections. His first visitor on Monday was Mr Cohen.
'He told me Miss Fraser wouldn't be dealing with it any more because she was too stressed,' Mr Purdey said yesterday. 'Then he said he'd looked at the cow, in his opinion it had BSE, was a welfare problem and should be put down.
'Half an hour later Christopher Budge arrived and I said 'Let's treat the cow' and he said 'I've got to get on to two experts I know, just so we know we're doing the right thing.' He phoned me at 6pm saying he'd contacted his expert who'd referred him to someone else.
'Next day Damson was down on the ground. I wanted to go to the High Court to force them to continue the treatment. Then Mr Cohen turned up again and I consented to her being put down. I'm just bloody angry about the whole business. Perhaps someone wanted to avoid the embarrassment of the treatment working.'
Mr Cohen declined to discuss his role, but said: 'Some of the impressions in the media have been distinctly misguided.'
Mr Budge said: 'I'd sought further information, with Mr Purdey's agreement, from someone in Cambridge, a man I trust implicitly who's good in this field. I wanted to know more about the pathogenesis on OP poisoning, a second opinion in the best interests of my client and the welfare of the animal.
'I was quite happy to treat the cow. If Mr Purdey's saying I wasn't then there's freedom of speech in this country.'
Jane Holman, of the Ministry of Agriculture, reinforced Mr Budge's denial. 'We took no steps whatsoever to stop the treatment,' she said.