Biden, who will become the oldest US president upon his January swearing-in, suffered the injury Saturday with Major, one of his two German shepherds.

The president-elect’s personal physician Kevin O’Connor initially said x-rays had not uncovered any “obvious fracture”, but added that an additional CT scan would still be done.

That scan “confirmed hairline (small) fractures… in the mid-foot,” O’Connor said in a subsequent statement released by Biden’s office.

He added that the former vice president, who won an election against Donald Trump in November, “will likely require a walking boot for several weeks”.

On Monday, Trump retweeted an NBC video of Biden leaving an orthopedic office in Delaware where he had gone for treatment, and added the caption, “get well soon.”