FROM LEFT: Simon, 8, Phillip, 10, grandpa Ephraim "Smiley" Cyprys, Jasmine, 4, and Galaxy.

FROM LEFT: Simon, 8, Phillip, 10, grandpa Ephraim "Smiley" Cyprys, Jasmine, 4, and Galaxy. Photo: Penny Stephens

Only a year or so ago the Weinstocks of East Bentleigh were thinking the unthinkable. Simon, nearly eight, their second son, might have to leave to live in care, for the sake of an already struggling family.

He is so severely autistic that he could barely talk. Simon was smashing his head through windows, not sleeping much and eating only white food. He was biting people and smearing faeces around the place. This was before Galaxy the dog arrived. Since then it has all changed.

Before the arrival of Galaxy, Simon was climbing manically and running away. The house had not yet been Simon-proofed. He would abscond into six-lane traffic on South Road. “A Houdini,” says his mother, Sarah. “An escapologist.”

Once, a driver tried to help but Simon jumped in the car and sat down and smiled and put the seatbelt on. The driver called the police. Simon started kicking the police car and screaming. The only way they could calm him, before someone from the neighbourhood who knew him intervened, was to put a police hat on his head and a breathalyser in his mouth.

“I love him,” says Sarah. “He's magnificent." She keeps his hair long and people often mistake him for a girl but he's a stunning boy with deep, glittering caves for eyes. "You could paint him," she says. "But he's of a different world and that's where he's trapped.”

Consider the rest of the family, too. Sarah is very large – obese – with attention deficit hyperactivity disorder. She can't move freely and has back pain. Eldest son Phillip, 10, is autistic as well, but not severely. Husband Michael has Asperger's syndrome and young daughter Jasmine, 4, is borderline Asperger's.

They're a loving family but it was always chaotic and often perilous. “There's nothing normal round here,” says Sarah. "This is a dynamic and tough household. We were overwhelmed and desperate.”

It came to a head when Jasmine was born and Simon was four and Phillip was six. Simon had not started at the Southern Autistic School in Bentleigh and the family did not yet have their nanny or helpers.

The questions about Simon posed unknowns. Can we look after him? Will he be all right? Would he ever taste freedom? How aware could he eventually become?

Then Sarah read about autism dogs for children. She tried to get one in Australia but couldn't (although they are available now from a charity in Bendigo) so she started the long process to get one from America because, four years ago, there had to be a circuit-breaker.

The family, with Sarah's father, Ephraim "Smiley" Cyprys, raised $20,000, mainly through Melbourne's Jewish community. The Pratt Foundation donated money to cover travel expenses to America — it was the late businessman Richard Pratt's last bequest, literally from his deathbed.

Galaxy cost $15,000. The family brought him back from Dayton, Ohio, in April, after three weeks of intense training with him. He came from 4Paws for Ability where he had already been trained for six weeks by prison inmates. The family love his name because they felt they went halfway across the universe to get him.

At the first encounter, Simon, who previously was scared of dogs, squealed with delight and patted the dog with his foot, then got in his kennel.

Now Galaxy is part of the family and they often wonder if the rangy, tender young field retriever knows exactly what he has got himself into. But everything feels like it has changed forever. In just six months Simon has developed dramatically. He has started saying more words and asking to go to the toilet.

“He's more than a dog," says Sarah. "It's a big job for him but so much has happened."

The way it works is the dog can intervene, protect and comfort and also provide emotional focus. If Simon is distressed or bewildered or obsessing — crying, screaming or having a tantrum — Galaxy will cuddle him by putting his front paws around Simon's shoulders to nuzzle him, breaking the cycle as well as giving comfort. The dog seems to know when this might happen rather than simply reacting. He might initiate the cuddle by nudging Simon with his nose.

The pair have a harness for walking but that's becoming less necessary. If Simon is climbing or wanders off, Galaxy follows and barks. "He can track him in seconds," Sarah says. "'Go find your boy.' He always checks his boy." Last weekend, Galaxy followed Simon into the water at Port Melbourne. They snack on peanut butter together — off the same spoon. "It's beautiful to watch," Sarah says.

The crucial changes, though, are to do with Simon's sensory needs. He likes to grab and be grabbed and he likes deep pressure. Galaxy both gives and takes; he sleeps on Simon's bed, lying across him. Simon now sleeps through most nights; he can even now sleep in the same room as his brother and the door can be unlocked. He provides an outlet for Simon to push and prod, things Galaxy has been trained to accept. Consequently Simon is calmer, and that calms the whole family. Friendship with the dog has made Simon more aware of others around him.

The science is unclear because it's a new idea. Monash University anthrozoologist Dr Pauleen Bennett says it may be that dogs' general closeness to humans provides "security" or it may be a specific release of "feel-good" hormone oxytocin, felt also by mothers bonding with babies. "We don't know why exactly," Dr Bennett said. "It's not always a happy-ever-after story. But where it does work it is phenomenal."

For the Weinstocks, where before there was worry and a kind of void, now there is hope. "I know Simon can feel love because of how he is with Galaxy and I also know he loves me," Sarah says. "We're positive about the future. I will never give up on my son."