CNN

Former Sen. Bob Dole was treated for a leg infection.

WASHINGTON (CNN) – Former Senate Majority Leader Bob Dole is recovering at Walter Reed Army Medical Center after surgery to treat a serious leg infection, according to a statement released by his press office Friday.

Dole, 85, was hospitalized last week after experiencing "a sharply elevated heart rate in the middle of the night," the statement said. Doctors determined that the former presidential nominee's heart was fine, but then discovered he had open sores on both of his legs. Surgeons quickly operated and "have since performed several procedures on his left leg," according to the statement.

"I am recovering nicely thanks to the great doctors, nurses and staff at Walter Reed," Dole said in the statement. "I have been coming to Walter Reed for over 40 years and I hope to be out by my birthday, July 22. It has been painful but I think I will be fine."

The statement noted that Dole's doctors believe his legs are healing properly. They are planning to perform a skin graft on his left leg Monday if his recovery continues as expected.

A close friend of Dole insisted that the former senator is in good spirits and has been pestering associates to bring him paperwork from his office at the law firm Alston & Bird to pass the time.

While greeting military veterans at the World War II Memorial in Washington late last week, Dole noticed skin irritation on his leg that led to bleeding, according to the friend.

–CNN's Ed Henry contributed to this report