9feeba01__RSPCA_Australia_knowledgebase__Relevant_Provision
[State] Western Australia [Legal? (Yes/No)] No [Relevant Provision] 
Regulation 14 of the Animal Welfare (General) Regulations 2003 (WA) states that a person who is not a registered veterinary surgeon shall not carry out the tail docking of a dog. A registered veterinary surgeon is only permitted to dock a dog’s tail if it is clinically indicated for the purpose of curing or alleviating disease or injury from which the dog suffers.
Is the tail docking of dogs legal? - RSPCA Australia knowledgebase
Relevant Provision