Two transit guards have come under fire for dragging an elderly man off a Perth train because he had a therapy dog with him.

Concerned passengers on the Mandurah train filmed the incident, and the footage shows the guards arguing with the man about the small dog that is with him.

The guards were filmed asking the man about his dog. Picture: 9NEWS (9news)

The man explained the dog was a therapy dog. Picture: 9NEWS (9news)

The man tried to explain that the dog is a therapy animal and the officers replied: “That is not grounds to have a dog on the train.”

The man appeared to show the officers proof of his medical condition, and tried to argue that he had permission from a transit officer at a previous station to have the animal on board the train.

“That would cause you anxiety having those officers in your face trying to take your companion away from you,” witness, Corey Hughes, told 9NEWS.

The guards dragged the main off the train. Picture: 9NEWS (9news)

After insisting the man still leave the train, the guards were filmed physically dragging him out of the carriage when he appeared to become agitated.

The guards continued to physically restrain him on the train platform and his dog was captured jumping up at his legs.

The public transport authority said the guards acted appropriately. Picture: 9NEWS (9news)

The public transport authority told 9NEWS the guards acted appropriately.