Dolphinaris announced in a release that Khloe, an 11-year-old dolphin, died Dec. 30 due to a parasite called Sarcocystis, adding that she suffered from the illness prior to her 2016 arrival at Dolphinaris Arizona.

11-year-old Khloe the dolphin dies at Dolphinaris near Scottsdale/ KPNX

“This infection usually causes severe central nervous system and muscle disease, as well as weakens the immune system to other pathogens,” Dolphinaris Arizona general manager Christian Schaeffer said in a statement. “Her condition has been managed with exceptional veterinary care for nearly six years as we called on dolphin experts globally to determine treatments that extended her life.”

In May, 10-year-old dolphin Alia died, and before her death, another dolphin named Bodie died in October 2017.

Animal rights activists have railed against the facility since it opened, saying it is not how the mammals were meant to be housed or treated.

The Dolphinaris release said that Khloe’s caregivers noticed her decline in health and “took every action possible to try and save her.”

Dolphinaris is located beyond Scottsdale city boundaries on the Salt River Pima-Maricopa Indian Community land.