Some tenancy agreements have an additional term that says you must have the landlord’s consent before you can keep a pet.
In strata schemes, some by-laws state that you also need to have written consent of the owners corporation. In some circumstances, an adjudicator and/or the Consumer, Trader and Tenancy Tribunal can make an order that the owners corporation has unreasonably withheld its approval to keep a pet.
Even if you have the consent of the landlord and the owners corporation, any other occupier can apply for an order to remove a pet on the grounds that it is causing a nuisance. By-laws cannot prevent you having a guide dog or hearing dog.