He tweeted a photo of his son, former President George W. Bush, visiting him in the hospital.
It was announced this week that George H.W. Bush was admitted to a Houston hospital as a "precaution" for a mild case of pneumonia.
Bush, 92, has been hospitalized with pneumonia since Friday.
Bush, 92, the oldest living former US president, has been hospitalized several times in recent years for a variety of problems. He was released from the hospital on January 30 after receiving treatment for more than two weeks.
"Big morale boost from a high level delegation", a Twitter post said on Bush 41's page.
McGrath said Bush was be gaining strength and in good spirits Wednesday, and he reported no other changes in the former president's status Thursday. Bush spokesman Jim McGrath said in a statement Tuesday, April 18, 2017, doctors determined he had a mild case of pneumonia which has been treated and resolved.
He is the father of former President George W. Bush, who served two terms in the White House from 2001 through 2009, and former Florida Governor Jeb Bush, who unsuccessfully sought the 2016 Republican nomination for president.
In February, Bush and wife Barbara, who was also hospitalized in January, took part in the pregame coin toss at the Super Bowl at NRG Stadium.