The four-year-old from Comber was born with Spastic Diplegia, a form of cerebral palsy, which affects his ability to walk as he could not straighten his legs.

There was no treatment available in Northern Ireland, but his parents discovered that an operation was available privately that could help his mobility- and so they created the Help Billy Walk campaign last year.

Thanks to the generosity of those who donated and helped raise the £50k, Billy received the operation in Bristol in July.

The operation, has improved things not just for Billy but for the rest of his family too.

Billy can now get about unaided and his big brother Robert is helping him learn to ride a bike, something his family never dreamed possible.

"He can walk around our kitchen, he can step up and down steps, he can get into a shopping trolley now, which before he couldn't get into a child's shopping trolley because his legs were too stiff," his mum Savien said.

He gets up out of his bed and walks into our bed in the morning which is just amazing, we never dreamt that he would be able to walk in in the morning and give us a cuddle.

Savien Douglas

She added: "He can ride his specially designed bike and he can just generally straighten his legs out more. He can wiggle his toes, he couldn't wiggle them before."

For his mum, it's the small things that mean most.

She said: "The best thing so far was having him walk around the shopping centre holding my hand, no sticks, no wheelchair or strangers looking at you strangely as they have always seen Billy in a wheelchair and now they are looking at a boy walking and it is an amazing feeling."

Billy will need one more operation to lengthen the muscles behind his knee, but his family are hopeful it can be done locally.

Their next goal is to secure physiotherapy that is crucial to Billy's recovery from the health service.