Tony Bird is still in hospital with serious leg injuries after being attacked by an an English Bull Terrier-type dog on Stourbridge High Street on Wednesday evening.
Police are now investigating after the owner and the dog left the scene, leaving Tony to find his own way to hospital.
The 55-year-old, from Norwich, was in the town on a business trip and had eaten at Bombay Pickles with his work partner Jon Gupta.
The pair left and headed down the High Street at about 10.30pm when the dog, which was being walked on a lead by a man, latched onto his leg.
The dog was attached for about 30 seconds before its owner managed to pull him off, Jon said.
"Rios Piri Piri takeaway on the High Street assisted with towels to cover his wound and also said that the dog had attacked one of his staff two days earlier," Jon explained.
"My business partner was taken to hospital and he's been there ever since.
"He had to have 86 stitches and the dog chipped some of his bone so they had to stitch the muscle too.
"If that had been a kid he'd have been dead.
"When we got to the hospital and they took the towels off, I'd never seen anybody with a dog bite so bad.
"Tony had the operation on Friday and he's hoping to be discharged soon."
Jon added: "The man said we were walking too close to him. He was white, had curly brown hair and was quite tall."
A spokesman for West Midlands Police said: "We were alerted to a man being bitten by a Bull Terrier-type dog in High Street, Stourbridge, on Wednesday evening.
"A man in his 50s was taken to hospital with serious leg injuries.
"Enquiries are continuing and anyone with information is asked to contact us via Live Chat, or by calling 101, and quoting log 4819 of 29th July."
Jordan Eggington, spokeswoman for West Midlands Ambulance Service, said: "We were called at 10.38pm on Wednesday to reports a patient had been bitten by a dog on High Street in Stourbridge.
"However, crews were stood down before arriving at the scene as the patient made his own way to hospital.”