Connyland Dolphins Died After 'Heroin' Overdose During Techno RaveTwo dolphins at a Swiss zoo have died after ingesting a heroin substitute drug during a "rave" at the centre, a post-mortem has shown.
The mammals died at Connyland zoo, Lipperswil after a weekend-long festival held near the dolphins' habitat.
A toxicology report released over the weekend showed that the two ingested buprenorphin, a drug used as a heroin substitute, which caused Shadow and Chelmers to die slowly and painfully.
It is almost certain that the two dolphins were given the drug at the weekend rave, organised by the Connyland park management, however they deny any wrongdoing in the treatment of the animals.
Their death was initially blamed on the zoo's vets, who were assumed to have given the dolphins incorrect medicine before the toxicology report finally revealed the real cause of the dolphins' death.
It is not clear who gave the dolphins the drug or whether it was a deliberate act.
Dutch marine biologist Cornelis van Elk added that the drug is incredibly dangerous for sea mammals.
"Opiates are extremely dangerous for underwater mammals.
"Even when sleeping - there is part of the brain that automatically controls the breathing instinct in the same way as it does for people when asleep," van Elk explained.
"Drugging them with opiates could well cause this part of the brain to switch off with fatal consequences."
Their keeper, Nadja Gasser, said that they dolphins died an awful death. Shadow died very soon after the event, with Chelmers dying five days later.
"The death was very drawn out and painful. The death went on for over an hour. It was horrendous. I have not been able to sleep since," Gasser said.
"He [Chelmers] was drifting under the water and was clearly in trouble and so we jumped into the water. We tried to hold him. He was shaking all over and was foaming at the mouth.
"Eventually we got him out of the water. His tongue was hanging out. He could hardly breath. He was given adrenalin, but it didn't help. After an hour the dolphin died."