(CNN) -- President-elect Joe Biden has hairline fractures in his "mid-foot" and will "likely require a walking boot for several weeks," his doctor said in a statement Sunday, after Biden slipped while playing with his dog, Major, Saturday.
"Initial x-rays did not show any obvious fracture, but his clinical exam warranted more detailed imaging," Dr. Kevin O'Connor said Sunday. "Follow-up CT scan confirmed hairline (small) fractures of President-elect Biden's lateral and intermediate cuneiform bones, which are in the mid-foot. It is anticipated that he will likely require a walking boot for several weeks."
Earlier Sunday, Biden's office announced he was going to be examined by an orthopedist "out of an abundance of caution" after he twisted his ankle playing with the dog.
Biden, who celebrated his 78th birthday on November 20, is set to be the oldest president in US history.
During the campaign, the Biden campaign released a summary of Biden's medical history, which showed the former vice president was healthy and fit for the presidency.
The release included the results of a physical exam by O'Connor, Biden's primary care doctor since 2009 and the director of executive medicine at The George Washington Medical Faculty Associates.
O'Connor wrote that Biden is "a healthy, vigorous, 77-year-old male, who is fit to successfully execute the duties of the Presidency."
The Biden family has two dogs, Major and Champ, both German Shepherds.
The Bidens fostered Major from the Delaware Humane Association and made his adoption official in November 2018. Champ joined the Biden family during the presidential transition in December 2008, weeks after Biden became vice president-elect.
This story has been updated with additional developments.
CNN's Betsy Klein and Eric Bradner contributed to this report.