The farmer at the centre of the foot-and-mouth outbreak has said his family are "devastated".
Roger Pride, who runs Woolford's farm near Godalming in Surrey with his wife Valerie, said they were victims of circumstances beyond their control.
In a statement read at a press conference by Anthony Gibson from the National Farmers' Union, Mr Pride described the moment when it was confirmed his animals were infected. He said: "For a moment we couldn't believe it. We were completely shocked and devastated. If felt as if our whole world was turned upside-down."
The farmer said that his father Derrick, who established the holding with his mother Sheila, first realised that some cattle in a field were "off colour and drooling" last Thursday.
Mr Pride also looked at the animals and a vet was called to examine them and advised the farmer to inform Defra. A vet from the Government department was on the farm 90 minutes later. The cattle were tested the next day and, at about 7pm on Friday, foot-and-mouth was confirmed by a phone call from Defra.
Investigations into the cause of the outbreak have so far focused on a research laboratory in Pirbright - close to the infected farm - which stores the disease for use in vaccines.
Mr Pride added: "Whatever the cause of the outbreak, it is obvious we have been the victims of circumstances far beyond our control. The theory that the sewer which overflows into part of the field where the 38 cattle were grazing could be the cause is an obvious possibility.
"Certainly no-one at the farm has had contact with the Pirbright facility."
Mr Pride continued: "We have always practised the highest standards of biosecurity at Woolford Farm, have been meticulous with our record keeping. No animals have been moved on to or off the farm since early June."
NFU spokesman Anthony Gibson said: "There is already incredulity and shock that this could - even could - have happened. There is shock in the farming community at the moment. This could turn to anger."
