Raleigh, N.C. — A North Carolina veterinarian who works with sea turtles said some of the animals he helped rescue from the Gulf of Mexico had traces of oil in their throats.

Dr. Greg Lewbart, a professor of aquatic animal medicine at North Carolina State University, returned Monday after more than a week on Gulf coast assisting the National Oceanic and Atmospheric Administration with cleanup efforts there.

On April 20, BP's Deepwater Horizon rig exploded gushing up to 130 million gallons of oil into the sea.

"We weren't on the front lines. We were, more or less, in a 'MASH unit' for turtles," Lewbart said. "I was encouraged by the turtles I saw. They were alert. Most of them were eating."

Lewbart helped rescue about 100 sea turtles. The biggest concern he saw was oil ingestion.

"What I don't know about is the long-term effect of any oil ingestion. It's really hard to know if or how much these turtles ingested," he said.

Turtles which get too much oil in their blood stream could become ill and die, Lewbart said.

Lewbart said he helped clean turtles with Dawn dish detergent. "We were using mayonnaise to bind up the oil around the eyes and in the mouth," he said. "You wouldn't think that would work, but it works really efficiently."

Overall, it is tough to determine the fate of the animals in the Gulf without knowing how much longer the oil spill will last, he said.

"We can't stop this thing. How can we start to fix it if we can't stop it?" he said. "And that's a big issue for the turtles."

Two other N.C. State veterinarians remain in the Gulf working to help the animals.