Officials said they can't pinpoint the type of toxin that killed 34 reptiles at a zoo in Knoxville.
The Knoxville News Sentinel reported Zoo Knoxville on Friday released necropsy results performed at the University of Tennessee.
University veterinarians determined a combination of swollen blood vessels, changes in the animals' livers and hearts, and the sudden deaths of multiple animals pointed to a toxic origin.
Zoo president and CEO Lisa New said the specific toxin can't be determined.
The animals found dead in March were mostly snakes. Also killed was a blue-tongued skink and a Gila monster. Eighteen reptiles survived.
New said the zoo will no longer exhibit or house animals in the building where the reptiles died.
