SeaWorld, which first announced Unna's illness in September, has sought to portray candida as a natural part of a wild orca's life, describing it as "pervasive in the environment" and saying it is found in wild whales and other animals. But the Merck Manual, a respected encyclopedia of veterinary medicine, reveals that the fungal infection is often a result of captivity.
"Captive marine mammals seem particularly prone to fungal infections," the manual says. "This common mycotic disease [candida] in captive cetaceans occurs secondary to stress, unbalanced water disinfection with chlorines, or indiscriminate antibiotic therapy."
Unna's infection was also resistant to antibiotic treatment, according to SeaWorld's press releases. According to former trainers, SeaWorld regularly doses its whales with antibiotics, which is inadvisable as it can lead to drug-resistant strains of funguses and other infections.