Dolphin's pregnancy worries aquarium

December 10, 1991|By Frank D. Roylance | Frank D. Roylance,Evening Sun Staff

Excitement has turned to worry at the National Aquarium in Baltimore, where one of two pregnant dolphins has apparently developed complications that may threaten her unborn calf.

The dolphin, named Hailey, is a "first-time mother, and she seems to be having an uncomfortable pregnancy," says marine mammal curator Doug Messinger. "It's got us very worried."

On the bright side, the aquarium's second pregnant dolphin, Shiloh, seems to be doing fine as her early March due date draws closer. That animal has had a calf before.

"She's almost as big around as she is long at this point, and we couldn't be happier," Messinger says.

Both animals are 12 years old. They were captured in the Gulf of Mexico in 1981, acquired from a Florida firm and flown to Baltimore in October 1990.

They became pregnant late last February or early in March, to the delight of the aquarium, which hopes to develop a breeding program for its marine mammals. The dolphins' gestation period is 12 months.

About a month ago, Messinger says, Hailey's handlers began to notice that her appetite was becoming more sporadic. She is now eating only a quarter to two-thirds of her full diet.

"She has always had a history of being finicky . . . but it's very pronounced now," he says.

Beyond that, he says, "you can tell just by her posturing, and when she comes over to feed, she doesn't have that sparkle in her eye. . . . You can just see she doesn't feel good."

In recent days, aquarium veterinarian Brent R. Whitaker says, blood tests have begun to show evidence of "liver compromise; we don't know why that is."

One possibility is that the growing calf is putting pressure on Hailey's liver, causing liver damage, he says.

Ultrasound examinations have shown the 7-month-old fetus is alive and developing normally, and there is no evidence of a liver infection. But "it is a large calf," Messinger says.

"It's possible that's making her uncomfortable, pushing against her organs. She's mature, but she is a relatively small dolphin."

Hailey weighed about 350 pounds when she became pregnant last March, 30 pounds less than Shiloh. The two males with which they mated weigh about 450 pounds each.

With three months still to go in the pregnancy, the aquarium staff is preparing for a crisis.

"We are anticipating that she would naturally abort the calf if it becomes too much of a burden on her body," Messinger says. "We hope that doesn't happen, but we're trying to be realistic."

What's less clear is what Whitaker would do should Hailey's life become threatened by the continuing pregnancy.

"Inducing abortion in these animals is very difficult because you can't assess whether there's a dilated cervix, and you may rupture the uterus," he says.

A Caesarean section is a possibility, but also full of risks.

Dolphins are thought to stop breathing when they're unconscious, making anesthesia difficult, although a few have been placed successfully on mechanical ventilators, Whitaker says.

Caesareans themselves are also "very dangerous" in these animals, he says. "I don't know anyone who has done it successfully." The risks of infection and suture failures following surgery are very high.

Still, he says, "if we knew the mother would die as a result of not doing something like this, we would bring in specialists . . . to try to give the animal the best shot at life as possible."

In the meantime, both Hailey and Shiloh have been withdrawn from the daily cycle of dolphin shows in the Marine Mammal Pavilion and are spending their time in a holding tank behind the large display pool.

Both are receiving special high-calorie diets, vitamin supplements, regular blood tests and weekly sonogram examinations. If her appetite falls off significantly, Hailey will receive additional nutrition and fluids by force-feeding.

"But at this point," Messinger says, "a lot of it is up to her. . . . All we can do is hope for the best."

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