The judge took the precaution of testing the learned doctor's capacity to translate from Caninese by a simple expedient; the judge's own dog was summoned to court and the doctor was told to obtain information about what the judge had eaten for supper the previous night. The dog gave extremely interesting information about what the judge had eaten and, indeed, what else he had spent the evening doing!
On this basis, Bob was allowed to appear in the witness box, despite the spluttering objections of the prosecutor. He was placed on a high chair and "sat scowling down over the rail upon the amazed and gaping jury". Bob's dignity and veracity reduced the prosecutor to a feebly murmuring wreck, who had to be helped out of court. Bob's master was acquitted forthwith.
Witnesses of this calibre are rare indeed among the human race, so I support the call for more diverse participants. I suggest a golden eagle as judge, with seagulls as jurors; and two or three rooks would make perfect court ushers.