Hugo, 15, has a rare neurological disorder and relies on his mountain bike for independence.
But he discovered his grey bike had been stolen while padlocked to a fence in Pimperne.
He used it to cycle a mile from his home in Pimperne to the village hall to catch the minibus that takes him to Victoria Special School in Poole and back again.
Hugo has recently had surgery on his legs and had only returned to cycling a few weeks ago.
His mother Lucy said: "He is a very brave boy and has just recovered from an operation to straighten both his legs.
"He has been devastated by the theft of his bicycle which has been essential therapy in straightening and co-ordinating his legs."
Hugo's father Russell added: "We never thought Hugo would be able to ride a bicycle. But he did it and cycling has given him the independence that he could only have dreamed of a few years ago.
"This bike was a birthday present - his first big bike and it's so special.
"We're just hoping that Blackmore Vale Magazine readers will know where it is and we can get it back. Without it we have to drive Hugo to get the school bus and pick him up and he feels he's lost his independence."
The grey GT mountain bike was stolen during the day on Thursday, 8th July.
It is distinguished by having two blue dragon transfers on the frame and one white transfer with the white head of a fox and the word fox.
Mr Lucas-Rowe said: "Hugo is a well known character in Pimperne cycling down the lane - walkers always encourage him on his way. We hope the thief will do the decent thing and return it or that a reader will spot it somewhere and get in touch."
Call Mr Lucas-Rowe on 07796 305611 with any information.
Dee Adcock