It is unlikely that your lawyer or a sitting justice would have the same attachment to your pet that you or your ex do. A pet is a chattel i.e. the same as any other piece of property owned by the parties such as a car or bedroom suite. A pet is not in an analogous position to a child. While courts will devote considerable time to custody and access case involving children, their patience with pet cases is short.
In Warnica v. Gering, 2004 CanLII 50065 Mr.Warnica commenced an application seeking "shared joint custody" of the pet dog, Tuxedo. The Respondent Gering also sought an order for custody of the Dog. Although the matter was originally commenced in the Ontario Court of Justice, which has authority over custody but not over property issues, it wound up, after some convoluted legal issues, in front of Superior Court Justice R. Timms. Justice Timm's noted: "… I do not believe that any court should be in the business of making custody orders for pets… If the Applicant were to have his way, there would be a trial, with viva voce evidence to determine… ownership of the dog. Prior to any trial, there would have to be at least one settlement/ trial management conference and an appearance in trial scheduling court." Justice Timm's concluded: "..this case must end here…"
Justice Timm's awarded ownership based upon the facts before him, without trial. He relied upon a Family Law Rule which allowed a court to dismiss or suspend a case if he regarded it to be a waste of the court's time. This order was appealed and the decision upheld by the Ontario Court of Appeal (Warnica v. Gering, 2005 CanLii 30838 (ON CA)) . Most judges would probably approach a 'pet custody' case in accordance with the findings of Justice Timm.