The Secret Life Of Dogs (ITV1, 9pm)
The Big Reunion (ITV2, 9pm)

MILLIONS of people in Britain share their homes with a dog, often confiding their secrets in them, and treating them like one of the family. But how much do we really know about our four-legged friends?

The Secret Life Of Dogs, narrated by Martin Clunes, isn’t a shocking expose about the dark side of canines but an insight into how the animals perceive the world around them, as well as explaining why they bark, how they curve their tongues to drink water, and whether they dream.

There’s also a reminder why dogs shouldn’t be taken for granted. Although they can be found in more shapes, sizes and varieties than any other mammal on the planet, they all share some incredible characteristics.

Dogs can hear noises from four times farther away than the average owner, and the part of their brains that controls smell is 40 times larger than in humans.

We also get to find out how these “super powers” are being put to work as we meet Max, one of Britain’s most successful search and rescue dogs. His handler, Alex Lyons, believes that when it comes to locating lost people, Max is worth ten human volunteers.

Margaret Haverson, from Exeter, would probably agree. The 79-year-old tried to take a short cut home after missing her stop on the bus, and ended up getting lost in overgrown woodlands. “I kept getting tied up with the brambles, then it got cold and dark so I lay under a big tree,” she recalls.

Police, volunteers and helicopters were all mobilised to find her, but it was Max who came up trumps. “I was very cold and very relieved when I was licked all over by a dog. He was so happy,” she says.

She isn’t the only one who owes a debt of gratitude to a dog. The documentary also tells the moving story of Navy officer Allen Parton, who suffered a severe head injury while on active duty in the Gulf war, which left him confined to a wheelchair and unable to recognise his wife and children.

He credits his labrador Endal with helping him reconnect with his family, but the loyal hound went even further to help when Allen was hit by a car. The dog’s extraordinary actions earned him the equivalent of an animal Victoria Cross.

Pets can also save our lives in slightly less dramatic ways. There’s evidence to suggest that dog owners live longer, and canines have been shown to make a positive impact on our mental and physical health.

But Maureen Burns believes her collie cross Max did more than just lift her spirits – he detected her breast cancer before the doctors did. “He would come up and touch my breast with his nose and back off, so desperately unhappy, with such a sad look in his eyes,” she says.

The Secret Life of Dogs look at the science that suggests Maureen’s hunch could well be right, as canines are capable of smelling the tiny volatile chemicals given off by cancerous tumours.

AH, those were the days – when all we had to worry about was updating our wall-covering posters of our favourite pop groups.

We’ve all been there, but for the children of yester-decade, it’ll please them no end that the likes of B*Witched, 911 and Atomic Kitten and co are giving it one more shot.

It’s for The Big Reunion, and the resulting one-off concert at London’s Hammersmith Apollo.

The programme comes a whopping ten years after the former celebs ruled pop, and while for many of them it’s a chance for another stab at the big time, for others, the reunion is going to open old wounds.

First up, the focus is on 5ive and Liberty X. But while the lads struggle to replace Jason J Brown who refused to take part, Michelle Heaton faces a serious surgery procedure.