Roger Potter's 450-acre dedicated free-range farm in North Yorkshire has thrived since it opened in 1984 but now it faces the possibility of Government restrictions and unease in the poultry market.
He has urged the public to continue buying eggs as there is "no risk" of infection – calls backed by environmental groups and unions
"I would urge people to use their common sense," said Mr Potter, who runs Yorkshire Farmhouse Eggs, at Catton, near Thirsk.
"Avian Flu is primarily a disease of wild birds and previous European outbreaks have been small, isolated and quickly dealt with. The Asian outbreak showed people have to be in very close contact with contaminated poultry and there is no risk to the public.
"As a producer I feel very confident in the preparations we have taken and our customers feel confident in knowing all our eggs are sourced locally from our farm with the highest level of quality control."
The Department for the Environment, Food and Rural Affairs (Defra) ran a mock exercise on Mr Potter's farm recently which simulated how they would follow the paper trail of infected birds. But officials have not told him to change his business practice since then.
"We are not in an infected area, there is no vaccination programme and we have not been told to keep our birds in," he said.
"In essence it is business as usual. Obviously it is a concern that it has reached these shores. It is a worry because it's our livelihood. Defra can't afford to get this wrong.
"We have to do what Defra says. I would like to vaccinate. They have already started vaccinating in Europe so surely if it became a major threat here we would do the same?"
Mr Potter said he could take his birds indoors if instructed to by Defra but if he does so for longer than 12 weeks he may not be able to market them as free range, even though they would be housed in his specially-adapted sheds with dust-bathing areas and extra room to move around.
"That would have a really bad effect upon us," he admitted.
"All our overheads are based upon free-range prices. The eggs would still have to be collected by hand."
And it would be worse if a cull of his flock was enforced, although he could implement emergency plans to keep his customers supplied with free range eggs from other sources.
"We would be out for at least a year if we were forced to totally re-stock," he said.
"It's a worry and we'd face an uncertain future. Hopefully this is an isolated case and there is a fair chance it could blow over."
Chris Kaufman, Transport and General Workers' Union national secretary for agriculture, said it was important to "keep the one case in proportion".
"No-one should be complacent. But, equally, one case should not make a whole industry vulnerable," he added.
The union called on the Government to risk assess poultry hatcheries and provide financial support for any workers laid off by the bird flu outbreak.
And British consumers were urged yesterday to keep eating poultry by the Soil Association.
Poultry adviser Anna Jonas said: "As long as you are not drinking the raw blood of chickens, then your risks are very low. We are talking about a disease of birds not humans."
The association said shutting flocks indoors might be necessary but warned farmers faced a "rapid cull" of their stocks if infected.
The Government told the association, which has called for strategic vaccination to contain any outbreak, it wanted to avoid the "mass culling and medieval funeral pyres" of foot-and-mouth.