St. Louis Zoo officials say the deaths of three harbor seals in transit from Canada to St. Louis last month were due to exertional myopathy, or a disease of the muscles. The disease was likely brought on by the stress of travel.
Zoo veterinarian Luis Padilla says the seals all succumbed to the same syndrome, which progressed at different speeds. Two seals died within a day of leaving their home in Ontario, while the third died days later at the Indianapolis Zoo where it had been taken for treatment.
Padilla says necropsies conducted on the animals concluded heat stress was not a factor in their deaths.
"For reasons that we haven't quite pinpointed," Padilla said, "there was a breakdown of their muscles and the byproducts of muscle breakdown is what led to their disease and their deaths."
Padilla says a forth seal that survived the journey is healthy and doing fine with 11 sea lions at the Zoo's Sea Lion Sound exhibit.
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