The documents were revealed through Freedom of Information requests and posted online. They are heavily redacted to protect the identity of Secret Service agents and secrecy of their security tactics.

They show at least 24 biting incidents took place between October 2022 and July 2023, including members of the Secret Service being bitten on the wrist, forearm, elbow, waist, chest, thigh and shoulder.

The documents do not necessarily record all biting incidents related to Commander, as they only cover the Secret Service and not others that work in the White House or staff at Camp David in Maryland.

The Biden family's pet left the White House in October last year, one week after a Secret Service agent required medical treatment for a severe bite.

A previous incident in June led to a "deep bite" on the forearm of an agent, who needed stitches. Blood on the floor in an area of the White House caused tours of the East Wing of the building to be suspended for 20 minutes, according to one document.

In July, another agent was bitten in the hand and required six stitches. The bite caused a "severe deep open wound" and the agent "started to lose a significant amount of blood", one email showed.

This agent was given a "small care package" by colleagues as a present including painkillers, antibiotic ointment, pepper spray, a muzzle and dog biscuits "for safety purposes".

An unnamed senior agent in one email advised that agents protecting Mr Biden and his family "must be creative to ensure our own personal safety".

"The recent dog bites have challenged us to adjust our operational tactics when Commander is present - please give lots of room (staying a terrain feature away if possible)," the agent wrote.