This is a NSW location. Sounds like very dodgy tenants.
I would be calling the police re: dope smoking / possession.
If the pets are being kept in breach of by-law then the tenants are also breaching their tenancy agreement. This is the approach to take with the managing agent. I would be writing to the managing agent officially seeking the S119 documentation and outlining the breaches of by-laws, threaten the managing agent with CTTT action if they do not deal with their tenant. And if the agent does not comply take them to the CTTT.
Alley Cat