Owners Lisa and Callu are worried about Merlin, a Great Dane who goes over on his front toes when he walks. Neurologist Annette Wessman suspects a problem in his spine or skull.

Journey around the world and discover how dogs became one of the most valued animals on the planet. From wild predators to friendly pets- this is the story of man's best friend.

Fisherman and adventurer, Jeremy Wade, is with a commercial fishing boat in Alaska, searching for giant halibut. Will they catch the sought-after 50-lb halibut?

When officers raid an illegal cockfighting ring, the quest for justice uncovers a shocking case of deliberate cruelty. But the bird's owner denies any wrongdoing.

In this special edition, join the rookies to discover what it is like learning to fight crime in one of the toughest cities in the US.

The Great Whites of Guadalupe are rigged with cameras for 18 hours to follow them into their secret hunting grounds, getting up close and wild.

The Brown family are ready to move into their new home when Ami requires immediate medical attention and must travel to a big city for surgery.

Jackson works with a couple whose lovable cat, Zachary, sprays all over the house. Plus, he meets up with troublemaking cat named Freddie Krueger.

The pandas in the Wolong Panda Reserve in China have been followed by camera teams for a year. Thanks to the pioneering research performed at the reserve, 16 cubs have been born.

Adventurous wildlife expert Saba Douglas-Hamilton goes on an extraordinary journey to reveal the true personality and secret life of the rhino.

Scientists have only recently begun to understand the true nature of our 'local star', the Sun. This program discusses its past and future, and its effect on our planet.

Dr. Jeff and Petra train new vets at a wildlife sanctuary in Mexico. While there, they spay an endangered jaguar, and help an injured osprey.

Comedian Bill Engvall requests a Zen-like fish tank for his new office in Hollywood. But a firm weight restriction throws a wrench in his plans.

A mission becomes personal when Miami's animal cruelty investigators find two adopted dogs wandering the city streets in need of help.

There's heartbreak as investigator Labrada fights to save a poorly dog that's been rejected by its owners. Plus, a young girl rescues a horse left without food or water.

Dr. Craig O'Connell and Andy Casagrande travel up the Serena River to try and find out why young bull sharks swim up the river, and how they avoid the crocodiles living there.

Explore the incredible creatures that inhabit Costa Rica, one of the most ecologically diverse places on earth. Meet the rare and secretive ocelot and puma, and much more.

Country superstar Zac Brown tasks Pete with building an otherworldly treehouse at Camp Southern Ground, a state-of-the-art camp for kids.

A new inmate starts working at VRC. Lizzy and Joe try to catch a stray in a nearby neighbourhood. A family wants to adopt a dog, hoping to fill a void in their hearts.

An expectant mother battles to keep a persistent feline out of her workspace and territorial cat puts a damper on his owner's love lives.

The pandas in the Wolong Panda Reserve in China have been followed by camera teams for a year. Thanks to the pioneering research performed at the reserve, 16 cubs have been born.

The team lend a hand at Lakota Reservation in South Dakota. Back at the clinic, Amy debates emergency surgery for a French bulldog who ate his favourite toy.

The Raneys create their first-ever self-automated homestead in the fierce Alaskan wilderness while firefighters Kim and Casey Boespflug are away on duty.

Surviving 400 miles from civilization boils down to one thing, finding food. Heimo pursues the animal that can feed him and Edna for months, a moose.

The Brown family are ready to move into their new home when Ami requires immediate medical attention and must travel to a big city for surgery.

Engineers are working on streamlining vehicles to improve fuel consumption and speed. Plus, a solar-powered car competes in an endurance race.

Investigators brave alligator-infested waters to help save an injured alligator. Meanwhile, 400 farm animals are rescued in Miami's biggest ever seizure!