The comedian and Beth Simpson, who married in 2007, already have a son together. Hound posted the news on Twitter along with a sonogram image taken at their first scan.
"Obviously, I'm hoping it's a) mine b) a cool wolf," he wrote. "Obviously we're chuffed to bits."
Simpson added: "We're due in July and nope, we're not finding out what flavour pup we have - I love a surprise after labour."
Hound recently competed in Channel 4's Famous and Fearless.