The dog was suspected of being an American pitbull terrier and impounded at the RSPCA in Burwood East under new state laws which ban pitbulls as restricted breeds.
The RSPCA supported the council officers’ initial assessment.
The dog’s owner, whose identity has not been made public, has appealed the decision at the Victorian Civil and Administrative Tribunal.
If VCAT upholds the council’s decision the dog will be the first pitbull to be euthanised as a result of the law since an amnesty on registering a pitbull as a restricted breed ended in September.
Nine Banyule dogs were registered as restricted breeds before the amnesty ended. There were six in Darebin and seven in Whittlesea.
Municipal Council of Victoria chief executive Rob Spence said there was still some confusion about whether dogs registered as American staffordshire terriers had to have pedigree papers or else were assumed to be pitbulls.
Mr Spence said councils would have to pay the cost of impounding these dogs, as well as the costs of VCAT proceedings if owners appealed.
Banyule City Council spokeswoman Trish Hosking said a full hearing was scheduled for February 22. She said no further details could be given.