* Seven countries badly hit by fifth year of drought
* High food prices, conflict worsen crisis
* Oxfam launches 9.5 million pounds ($15 million) appeal
(Corrects to sterling in bullet point and 2nd paragraph)
By Frank Nyakairu
NAIROBI, Sept 29 (Reuters) - Drought for a fifth year running is driving more than 23 million east Africans in seven countries towards severe hunger and destitution, international aid agency Oxfam said on Tuesday.
Launching a 9.5 million pound appeal, it said the situation was being worsened by high food prices and conflict. The most badly hit nations are Kenya, Ethiopia, Somalia and Uganda.
Malnutrition is now above emergency levels in some areas and hundreds of thousands of valuable cattle are dying.
"This is the worst humanitarian crisis Oxfam has seen in east Africa for over ten years," Paul Smith Lomas, Oxfam's East Africa Director, said in a statement.
He said failed and unpredictable rains were ever more common in the region, and that broader climate change meant wet seasons were becoming shorter. Droughts have increased from once a decade to every two or three years.
"In Wajir, northern Kenya, almost 200 dead animals were recently found around one dried-up water source," Lomas said.
"People are surviving on two litres of water a day in some places -- less water than a toilet flush. The conditions have never been so harsh or so inhospitable, and people desperately need our help to survive."
Some 3.8 million Kenyans, a tenth of the population, need emergency aid, Oxfam said, partly because food prices have risen to 180 percent above average.
One in six children are acutely malnourished in Somalia, the charity said, while conflict meant people were less able to grow food and drought is ravaging areas where people have fled. Half the population -- more than 3.8 million people -- are affected. In Ethiopia, 13.7 million people are at risk of severe hunger and need help, Oxfam said. Many are selling cattle to buy food. Farmers in northern Uganda have lost half their crops.
Other countries hard hit are Sudan, Djibouti and Tanzania.
Rains are due next month, but are likely to bring scant relief or even deluges that could dramatically worsen matters.
Oxfam said there were fears that east Africa could be hit by floods that would destroy crops and homes, as well as increasing the spread of water-borne diseases.
"The aid response to the crisis needs to rapidly expand, but it is desperately short of funds," the charity said, adding that the U.N.'s World Food Programme was facing a $977 million donor shortfall for its Horn of Africa work over the next six months.
"Even with normal rain, the harvest will not arrive until early 2010. People will still need aid to get them through a long hunger season," it said. (Additional reporting and writing by Daniel Wallis; Editing by Tim Pearce)