An alligator at the Oklahoma City Zoo died unexpectedly, but what veterinarians found inside his stomach was even more unexpected: seven plastic water bottles.
Zookeepers continuously pick up debris that blows or falls into animal exhibits, but this was a bit of a shock, said Jennifer D'Agostino, veterinary services director for the zoo.
"Animals get sick," D'Agostino said. "It happens. But this is something they get sick from that's totally preventable. Anything we can prevent, we want to prevent."
Using an arthroscope, D'Agostino and her staff checked the rest of the gators' guts for indigestible debris in the past few weeks. They found coins, bottle caps, more plastic bottles and even a child's shoe. One alligator had swallowed a little plastic alligator.
They have one more alligator to check.
The veterinarians pulled out the small items, like coins. But they're still trying to figure out how to pull out the big things without major surgery, D'Agostino said.
The trash will have to come out eventually. The seven water bottles found inside the dead alligator created a blockage that prevented the animal from digesting his food correctly, D'Agostino said.
Eventually the blockage became infected, and that infection spread to the rest of his body.
Some litter blows into the exhibits, D'Agostino said. A few items end up in the exhibit on purpose. Most of the coins are thrown into the pond by visitors making wishes. Some items are dropped accidentally; other things are thrown out of ignorance or malice.
Alligators release heat through their wide open mouths, she said. Some visitors see the jaws as target practice.
"People will actually chuck coins right into their mouths," she said. "They don't have a spitting reflex like a mammal, so the next time they eat anything, they'll swallow them."
The alligator isn't the first animal to die because of foreign objects, D'Agostino said.
Brindle, a seal, died of metal poisoning in June 2007. When the seal was examined after death, 92 coins were discovered in her stomach. Her stomach acid triggered a reaction with the zinc in pennies. The toxic result was kidney failure.
Like the alligator exhibit, visitors sometimes throw money into the pool to make a wish. Coins that spin as they sink reflect sunlight, mimicking the appearance of a fish, D'Agostino said.
The effect is a lot like that of a fishing lure.
Keepers now X-ray the seals and sea lions twice a year. Any debris is removed.
But checking the alligators isn't so easy, D'Agostino said. Their stomachs can't be X-rayed. Each scale has a bone inside, so the armor prevents veterinarians from seeing beyond the scales.
An arthroscopic camera reveals the stomach contents, but anesthetizing, scoping and evaluating the alligators several times a year isn't ideal.
So zookeepers are working to educate the public about animal health and safety, she said.
They may modify the exhibits a bit to catch some of the falling debris.