Sudan, the last male of remaining known northern white rhinos in the world, is seen in central Kenya's Ol Pejeta Wildlife Conservancy, on April 28, 2016. (Xinhua/Pan Siwei)

NAIROBI, March 2 (Xinhua) -- The only remaining male northern white rhino in the world named Sudan has developed a severe infection on the back right leg hence complicating its ability to walk and forage for pasture, conservationist said on Thursday night.

According to a statement from Ol-Pejeta Conservancy located in northern Kenya that has sheltered Sudan since 2009, the iconic mammal is yet to regain health even after advanced treatment from veterinary doctors from across the world.

"We wish to inform everyone that Sudan, the last male northern white rhino on the planet is starting to show signs of ailing. At the advanced age of 45, his health has begun deteriorating, and his future is not looking bright," said Eloide Samper, Communications Manager at Ol-Pejeta Conservancy.

Sudan has attracted the attention of local and international wildlife campaigners since its arrival in the Ol-Pejeta Conservancy in northern Kenya nine years ago.

It has defied old age, poachers and climatic stresses to become the only male northern white rhino alive in the world.

Sampere revealed that Sudan started becoming frail at the end of last year when its right back leg suffered a lethal infection.

"At the end of 2017, Sudan developed an uncomfortable age related infection on his back right leg. It was immediately assessed by a team of vets from around the world, and responded well to treatment, healing quickly," said Sampere.

"He resumed normal movement and foraging habits over January up to mid-February, with his demeanor and general activity improving significantly," she added.

Sampere regretted that a secondary and much deeper infection was recently discovered beneath the initial one hence worsening the ill health of a globally renowned rhino subspecies.

"The infection has been treated, but worryingly it is taking longer to recover, despite best efforts of his team of vets who are giving him 24-hour care, with everything possible being done to help him regain his health," said Sampere.

"We are very concerned about him; he is extremely old for a rhino and we do not want him to suffer unnecessarily," she added

Sampere disclosed that veterinary doctors have put Sudan under pain killers and antibiotics to stabilize his fragile health.