WASHINGTON – Two of the newly acquired Asian small-clawed otters at the National Zoo have died, officials say.
The Zoo announced two young adults from a family of 13 died late Thursday after routine quarantine exams.
Officials say the otters most likely died from ingesting a dye that was used to identify seven otters during the exams.
During the testing, the animals received contraceptive implants. When they were reintroduced to the family, the otters appeared to be eating and acting normally, Zoo officials say.
Keepers noticed Thursday afternoon that a female and male were showing discomfort while moving around. They were treated at the Zoo’s hospital, but both otters died.
A preliminary necropsy suggests the animals had methemoglobinemia, a condition that affects oxygen transport by the blood, which caused liver and kidney damage.
Officials say the dye is routinely used by wildlife researchers and professionals on birds, marine mammals and small mammals. The Zoo has used the dye for more than 30 years on numerous species, including golden lion tamarins, prairie dogs, black-footed ferrets and other otters that have lived on Asia Trail.
The excess dye was cleaned off the other otters. The remaining 11 others appeared to be acting normally Friday. They are in quarantine under close observation.
The National Zoo says it has stopped using the dye.
The Zoo has been holding a naming contest with Whole Foods to name the 13th otter. With news of the death of the two otters, Zoo spokesperson Pamela Baker-Masson says Whole Foods is deciding how to handle the contest.