The pit bull, named Tyson, escaped from a garden in Treetops Drive, Willenhall, and attacked the spaniel which was being walked by Anthony Hutchinson, Walsall Magistrates Court heard on Monday.
Ben Barker admitted being the owner of a fighting dog and a dog dangerously out of control in a public place.
Mrs Aliya Rashid, prosecuting, said: "It grabbed the spaniel by the ear and neck, swung the dog around and knocked Mr Hutchinson off his feet."
The court heard that 20-year-old Barkertried to prise open the jaws of the pit bull.
The spaniel had to be treated by a vet and
bills amounted to around £350.
Miss Sarb Sehmi, mitigating for Barker, of Longwood Rise, Willenhall,
said he had been given the dogin a pub. She said: "He didn't realise it was a pit bull. Had he known, he wouldn't have taken responsibility for the dog."
Judge Michael Morris
sentenced Barker to16-weeks in a young offenders' institution, suspended for 12 months. Barker was also ordered to carry out 160 hours' unpaid work and pay £500 compensation. A destruction order was made for the pit bull and Barker was banned from owning a dog for 10 years.
