[Columbia, SC] - Riverbanks Zoo and Garden released today that its six-year-old male koala, Mirai, has been diagnosed with lymphoma.

During a routine examination on January 11, Riverbanks' animal care staff discovered a mass growing underneath the skin on the right side of Mirai's neck. Riverbanks' koala management program calls for keepers to routinely examine the koalas' outward appearance, and the mass had not been noted the previous week. Mirai was anaesthetized, the 3-4 cm tumor was removed and samples were sent to the University of Georgia's Zoo and Exotic Histopathology Service and Lexington Medical Center's Department of Pathology for examination.

On Friday, January 13, Zoo officials received a preliminary report that the tumor was indeed cancerous. A formal biopsy report was received this week indicating that Mirai has malignant lymphoma, a known cause of mortality in koalas. Lymphoma, a tumor of lymphoid tissue, can affect many sites in the body.

"Mirai's prognosis is not good," said Satch Krantz, executive director of Riverbanks Zoo and Garden. "Traditional cancer treatments that might be successful for humans have never been successful for koalas. Koalas are fairly robust, but they can be highly sensitive to medical treatment. At this point we want to insure that Mirai's quality of life is not compromised."

Koalas in captivity can enjoy life spans of up to 10 to 12 years, but in the wild, mortality at Mirai's age is not uncommon. Riverbanks veterinarians do not expect Mirai to live more than a period of weeks to months. Until his condition worsens, he will remain in the Koala Knockabout complex where he is most comfortable.

Mirai is one of four koalas that were presented to Riverbanks Zoo and Garden in 2002 as a gift from South Carolina's Australian sister-state, Queensland. Mirai and another male, Kei, traveled from Hirakawa Zoo in Kagoshima City, Japan. The Zoo's two females, Lottie and Killarney, came from Australia's Walk-About-Creek Wildlife Center in Brisbane Forest Park and the David Fleay Wildlife Park, respectively. Kei died in 2003 as a result of a gastrointestinal problem. In 2004, Mirai sired his only offspring, a joey named Karoo, with first-time mother Lottie. Karoo unfortunately died in May 2005, a fairly common outcome for first-born koala offspring.

South Carolina and Queensland are partners in projects that aim to benefit koalas living in zoos and in the wild in Queensland.