...and then there's this...
...so that should take care of the people wanting to marry their pets, as it would not be possible to legally consummate the marriage without breaking the law...
Bestiality
160. (1) Every person who commits bestiality is guilty of an indictable offence and liable to imprisonment for a term not exceeding ten years or is guilty of an offence punishable on summary conviction.
Compelling the commission of bestiality
(2) Every person who compels another to commit bestiality is guilty of an indictable offence and liable to imprisonment for a term not exceeding ten years or is guilty of an offence punishable on summary conviction.
Bestiality in presence of or by child
(3) Notwithstanding subsection (1), every person who, in the presence of a person under the age of fourteen years, commits bestiality or who incites a person under the age of fourteen years to commit bestiality is guilty of an indictable offence and liable to imprisonment for a term not exceeding ten years or is guilty of an offence punishable on summary conviction.
R.S., 1985, c. C-46, s. 160; R.S., 1985, c. 19 (3rd Supp.), s. 3.
...so that should take care of the people wanting to marry their pets, as it would not be possible to legally consummate the marriage without breaking the law...