Zoo workers ran a drill "simulating the escape of a gorilla" on Monday, said the Loro Park zoo, a popular holiday destination in Spain's Canary Islands off the coast of Africa.
"One of the animal keepers of the terrestrial mammals was accidentally hit by a tranquillizer dart which the veterinarians have to have ready for such cases," Loro Park said in a statement.
Emergency medical services treated the keeper and sent him to the University Hospital of Tenerife, which discharged him Thursday after he had recovered from his gorilla tranquillizer shot.
"The employee has fully recovered," the zoo said.
A spokeswoman for the Loro Park zoo, Patricia Delponti, denied a Spanish newspaper report that the keeper had been dressed in a gorilla suit, confusing the vet who then shot him with the dart.
"He was not in disguise and the vet did not get confused about anybody. It was an accident," she said in a statement to