The Food and Agriculture Organisation (FAO) on Thursday warned of a major new foot-and-mouth outbreak in Egypt which could threaten the whole of North Africa and the Middle East.
"Urgent action is required ... to prevent its spread throughout North Africa and the Middle East, which could have serious implications for food security in the region," the UN agency warned in a statement.
In Egypt, official estimates speak of more than 40,000 suspected cases, with more than 4,600 animals, mostly calves, already dead.
While foot-and-mouth disease has circulated in Egypt for some years "this is an entirely new introduction of a virus strain known as SAT2, and livestock have no immune protection against it," FAO said.
"With vaccines urgently needed, international and regional organizations are at the ready to assist in developing a regional prevention, preparedness and action plan," the organisation added.
The UN body said it was working with the government in Egypt to bring the outbreak under control.
"The area around the Lower Nile Delta appears to be severely affected, while other areas in Upper Egypt and the west appear less so," according to Juan Lubroth, FAO's Chief Veterinary Officer.
Farmers have been urged to limit animal movement, avoid buying animals, and to burn or bury the carcasses of dead animals.
According to FAO's livestock census data, 6.3 million buffalo and cattle and 7.5 million sheep and goats are at risk in Egypt.
Vaccines for the new virus strain are currently in limited supply and vaccination often takes up to two weeks to confer immunity, FAO said, while urging anti-contamination measures.