The man was walking with his dogs on Sunday afternoon at Soldier’s Cove when the attack occurred.
Mandurah officer-in-charge Senior Sergeant Stephen Thompson said police responded quickly to the incident.
Sgt Thompson said the victim was being called names by the attacker.
The victim was then allegedly sprayed in the face with an aerosol deodorant. This resulted in the victim restraining the attacker.
It was then that the victim was allegedly bitten by the assailant.
Police arrested the alleged attacker, who was released on bail to appear in court on April 19.
The bite victim was admitted to hospital to be tested for blood-borne viruses.