An American dad was fatally injured after saving his five-year-old daughter from being mauled by a dog.

Robert Joseph Quick (33), from Iowa in the US, reportedly collapsed after a “large, aggressive” dog attacked him on Friday 31 May, Fox News reports.

The dog, who was kept at their home for a family member, reportedly first attacked his young daughter and the heroic dad of four intervened.

Upon arrival, local police were forced to shoot the dog because it wouldn’t let go of Robert.

“The dog was very aggressive and wouldn’t release the man,” the Fort Madison Police Department said in a statement. “Quick had defended his daughter and undoubtedly saved her life by his actions.”

Quick, a mechanic by trade, was rushed to the Fort Madison Community Hospital where he was later pronounced dead by medics, Metro reports. It’s thought he suffered a heart attack.

The little girl was bitten in the face but survived the attack.

An online obituary described Robert as a “loving” father and husband.

“He enjoyed working on and collecting cars, camping, music, fishing and spending time on the river,” the obituary read. “Joe especially loved his children.”

The family has set up a GoFundMe page to help for Quick’s funeral, ABC reports.

Sources: Fox News, Metro, ABC News