Apart from the fact that a proposed By-Law is not binding upon occupants until it’s Registered with the Plan of Strata Title, and any that are eventually Registered must be listed individually for discussion and possible amendment at the first General Meeting of the Owners Corporation, an animal’s weight is a ridiculous criterion that’s very likely unenforceable – like what would happen if your dog weighed 14kG upon arrival at your Unit and then ate like a horse thereafter?
So don’t worry about it; your dog’s probably just big-boned anyway!