Prince Charles has proposed a solution to the growing crisis of antibiotic over-use in animals and humans, telling an international gathering of scientists and government officials in London that he treats his own cows and sheep with homeopathy.

In front of the government’s chief medical officer, Dame Sally Davies, who once told a parliamentary committee that homeopathy in humans was “rubbish” and that she was “perpetually surprised that homeopathy is available on the NHS”, the prince explained to delegates from 20 nations and organisations why he had turned to homeopathic remedies for animals.

“It was one of the reasons I converted my farming operation to an organic – or agro-ecological – system over 30 years ago and why we have been successfully using homeopathic – yes, homeopathic – treatments for my cattle and sheep as part of a programme to reduce the use of antibiotics,” he said.

The prince did not give details or stay for questions, but Clarence House later said: “Homeopathy is used on a case-by-case basis at Home Farm, in combination with more conventional medicine, to minimise dependence on antibiotics.”

The prince’s belief in homeopathic medicines for humans has long been known, as well as his support for homeopathy in the NHS. It has sparked clashes with doctors and scientists who say the remedies, which involve a drop of active substance diluted in so much water that only “the memory” of the substance remains, are not evidence-based. There have been some experts, however, who have conceded that homeopathy could have a placebo effect for those who believe it will help them.

Cows and sheep are unlikely to experience this benefit, although a group called HAWL (Homeopathy at Wellie Level) which trains farmers in its use and is funded by the prince, said it can help animals that are stressed.

“It is now well accepted that problems come at times of stress (weaning, transportation, seperation etc), and giving animals remedies at these times may well avoid disease, but it may also improve production,” its website stated. It acknowledged, however, that scientific evidence for homeopathic remedies in animals is scarce.

There are 500 farmers trained in homeopathy and 38 homeopathic vets, according to the Department for Environment, Food and Rural Affairs. A spokesperson for Defra said animal remedies “must be registered in accordance with the Veterinary Medicines Regulations to ensure they are safe and labelled appropriately before they can be sold in the UK. Animal owners should always discuss the best treatment option with their vet and seek their professional advice.”

But the British Veterinary Association, the leading representative body for vets in the UK, dismissed homeopathy out of hand.

“BVA cannot endorse the use of homeopathic remedies, or indeed any products making therapeutic claims, which have no proven efficacy; the consequence could be serious animal health and welfare detriment because of the lack of therapeutic effect, which would be counterproductive to best animal health and welfare,” said John Blackwell, its senior vice president.

The prince’s categoric condemnation of the over-use of antibiotics in farming and in humans, however, will be universally welcomed.

“Given the potentially disastrous scenario we face, I find it difficult to understand how we can continue to allow most of the antibiotics used in farming, many of which are also used in human medicine, to be administered to healthy animals,” he said. “Would we, I wonder, advise adding antibiotics to our own food or water on a daily basis, just in case we became ill?”

Davies, the chief medical officer, who has twice visited the prince’s farm to admire its sustainable approach and minimal use of antibiotics, said she was delighted that he had agreed to sponsor the London meeting.

“He’s an organic farmer who has cared all his life for animal welfare and he hardly uses antibiotics,” she said. “His sponsorship means we have a very senior set of people here from around the world.”

Asked what she thought of his use of homeopathy, she answered: “I’m not a vet.”