What Life Is Like for This Family Circus of Lion and Tiger Trainers

— -- Alex Lacey and Katie Azzario-Lacey get to travel for a living -- but the one catch is that their luggage includes 700-pound animals.

The husband and wife duo are animal trainers with the famous Ringling Brothers and Barnum and Bailey Circus.

“I remember the first time I was actually in the cage with these guys, without this netting in between, these guys seemed at least 10 times bigger than they really were and I was absolutely petrified,” Alex Lacey told ABC News’ “Nightline.” “They can each eat up to 16 pounds of meat every day. … Our meat bill is $5,000 a week.”

Watch the full story on ABC News’ “Nightline” TONIGHT at 12:35 a.m. ET.

Lacey, 40, is a big cat trainer and presenter. When the lions and tigers are not eating, sleeping, performing or training, they’re kept in cages for everyone’s safety. Alex Lacey said he thinks the animals enjoy being in the circus.

“We don’t declaw any of the cats. We don’t take their teeth out,” Alex Lacey said. “If you’re going to keep any animal in a captive environment, you can’t expect them to live in a beautiful enclosure for the rest of their lives and do nothing.”

Alex Lacey’s parents owned a zoo and started training the animals. They then joined the circus.

His mom, big cat trainer Susan Lacey, lives in the trailer next door to them, and his brother, Martin Lacey, is also a big cat trainer based in Germany.

“He works an act with 28 lions and tigers. It’s the biggest act in the world at the moment,” Alex Lacey said.

Katie Azzario-Lacey, 27, and her sister were acrobats, and their parents were both clowns. Now, she is a mixed animal trainer, working with the llamas, alpacas, donkeys and a kangaroo that are part of the act she presents with her husband.

“I’ve been working with animals for about a year,” Azzario-Lacey told “Nightline.”

Most of the circus -- around 300 people -- travel the country and live on the circus train. Alex and Katie Lacey have a pickup truck, a motorcycle and a double-wide trailer. They live next door to their animals.

“Everybody knows everybody. Even if you haven’t worked together, you’ve heard of them and their family,” said Azzario-Lacey.

Though there are people who believe such captivity of animals is fundamentally cruel, Alex Lacey claims they’re aiding conservation efforts.

“As long as you provide them with an environment that allows them to eat, sleep and reproduce in comfort then they are content,” he said. “People don’t really care about things unless they’ve smelt it, felt it, seen it with their own eyes. That’s a great part of what we do.”

Alex Lacey said he loves getting to spend every day with his beloved wild animals, especially when they perform for their audiences.

“The people see what a great relationship I have with the animals, how much they trust me,” Alex Lacey said. “But at the same time, they want to see the growling and the snarling. Those cats naturally do that. So that’s what they do in the show.”

ABC News’ Nick Watt contributed to this report.