Dr. Reidenberg had to begin the dissection in Ireland by dealing with the bacterial gas that was building to dangerous levels inside the whale’s carcass. “It was inflating like the Hindenburg,” she said. “If you cut in too deep, you end up with a million sausage links all over the place.”

Her solution was to knife a series of holes in the whale’s throat. “It’s like defusing a bomb,” she said. A rush of wind came from each one, producing a symphony of flatulence. It took an hour for all the gas to exit.

Next, she used a meat hook to haul herself about 10 feet up to the top of the 65-foot-long animal, where she carved long incisions into its side. A digger from a local construction company was used to peel away the blubber in long strips. Now Dr. Reidenberg could cut open a doorway into the whale’s gut and haul out the intestines. The next morning, she climbed into the abdominal cavity, where each organ told its own story. She located the vestigial pelvis, a reminder of whale ancestors that lived on land. She extracted the voice box, which was bigger than she was.

After two days of this, she went back to her hotel and tried to clean off the whale grease. Fifteen showers and three baths later, she still had to make up excuses on the flight to New York; it took days for the grease to completely evaporate from her skin.

A couple of weeks later the television producers, happy with their footage, asked her to return, this time to dissect a tiger in London. She went. They called back, again and again, and she returned, to cut open a python, a polar bear, an elephant, a shark and other big animals, all the while explaining their inner workings.

Dr. Reidenberg, 50, had her first encounter with anatomy as a high school student interning for a veterinarian in Norwalk, Conn. The sight of a dog being opened up for surgery captivated her. “We’re so used to looking at the outside of the animal — look how pretty it is, look how fast it can run,” she said. “But there’s a lot of prettiness on the inside that people miss.”