World's last surviving male northern white rhino 'starting to show signs of ailing'

The world's only surviving northern white rhino "is starting to show signs of ailing", conservationists have said.

The rhino, named Sudan, became a global icon after park rangers were forced to put him under 24-hour armed guard to protect him from poachers in 2015.

But vets treating are concerned after discovering a new infection “much deeper” than one they recently treated in his right rear leg.

He recovered from the initial scare earlier this year, but is now taking much longer to recover from the second infection.

“Everything possible is being done to help him regain his health,” the Ol Pejeta Conservancy, which looks after the 45-year-old animal at its base in Kenya, said in a statement on Twitter.

“We are very concerned about him - he's extremely old for a rhino and we do not want him to suffer unnecessarily.”

Scientists are racing to develop IVF techniques that might keep Sudan’s lineage alive, using eggs from the world's last two northern white rhino females, who live at the same conservancy.

The females, a mother and daughter, have medical conditions that prevent them from conceiving naturally.

Fertility experts have taken three eggs from three southern white rhinos, a less rare breed, that are kept at Longleat Safari Park.

The nine eggs from the female southern rhinos were transferred to the Avantea laboratory in Italy, where they will mature.

They will then be fertilised in the lab using sperm from Sudan and also from several deceased southern rhinos to test the IVF procedure.

Conservationists hope the research will pave the way to producing viable northern white rhino embryos.

If successful, the IVF embryos will be implanted back into a group of females later in 2018.

The northern white rhino has been hunted and poached almost to extinction for its horn.

Powdered horn is used in traditional Chinese medicine to treat a range of ailments including fever, rheumatism and gout.