TEENAGER Beth Jeans never goes anywhere without her beloved dog Billy. But he is more than just her pet - he is her lifesaver.

For the 16-year-old student has a severe form of diabetes which means her blood sugar levels can suddenly drop or rise without warning, putting her at risk of convulsions or coma.

But Billy is trained to identify the subtle scent changes that occur in Beth’s body chemistry when her blood glucose levels change.

The clever canine alerts Beth by licking her hand and whining so she knows when to take her medication.

He will also fetch her insulin kit on command and place it on her lap.

Beth’s mum Jayne says the chocolate Labrador has transformed her daughter’s life.

“He has totally changed her life in so many ways. She has got her independence back because we could never leave her on her own before she had Billy.”

Beth is what’s known as a “brittle diabetic” and was diagnosed at the age of 11.

“At first she used to get warning signs such as tingling in her hands or shaking, but that stopped after a few years and then she would either just collapse or her legs would go numb and she couldn’t move,” says Jayne.

“On one occasion she fell and hit her head on a wooden floor. Somebody always had to be with her to make she didn’t go into a coma.

“It really affected her confidence and she became depressed and never used to want to go out anywhere.”

But then Jayne heard about a Dorset-based charity called Friends of Wessex Assisting Dogs (FWAD) which was launched in 2009 to provide support for people with disabilities.

“I’d seen a TV programme about how medic alert dogs could help people with diabetes.

“We are a quite an animal-minded family and I thought it sounded like a brilliant idea so I got in touch with Friends of Wessex Assisting Dogs in January last year.”

Beth was accepted as a suitable candidate and following a £4,000 donation from North Bournemouth Round Table, Billy joined the family last October.

“Now people come and chat to Beth about Billy so he is a good conversation starter too. He will also accompany her on the bus when she starts college in September.”

Researchers in the United States have discovered that a dog’s super sensitive nose has more than 40 times the number of smell receptors and are believed to be several thousand times more powerful.

Carole Cluett of Parkstone, founder of FWAD, says that even the most expensive and high-tech diagnostic tool cannot rival the nose of a dog.

“It is also being used in cancer detection too, particularly in prostate and lung cancer which can be difficult to diagnose in the early stages.

“In one study, the breath of a patient with lung cancer was frozen and five years later the dog was still able to identify it.

“The possibilities in this field seem endless. They really are man’s best friend. They work tirelessly but they thoroughly enjoy it – it becomes a way of life for the dog.”

It costs around £13,000 to train a medic alert dog using scented cloths and a reward system.

They can also be trained to respond to heart attacks and to detect pending seizure in epileptics.

• The Great Dorset Talent Contest will be held at the Lighthouse theatre in Poole on Saturday, July 23 to raise funds for Friends of Wessex Assisting Dogs. For more information and tickets visit fwad.org.uk