Police spent hours trying to keep a "large aggressive dog" under control after it bit a man on Thursday afternoon.
After six hours of trying to get the dog under control, police said it was "humanely destroyed" in order to protect the public.
South Wales Police were called to help a man who had been bitten on the leg by a Presa Canario-type dog in Wildmill in Bridgend on November 14.
The man was taken to hospital for treatment after the incident, which happened at around 4.15pm.
Officers spent a number of hours trying to subdue the dog but said they were unable to bring the it under control.
It was put down later that evening.
A spokesman for South Wales Police said: "We were called to reports of a man being bitten by a large aggressive dog in Wildmill, Bridgend at about 4.15pm.
"Officers attended and managed to contain the dog and for a number of hours tried numerous methods to subdue it.
"Veterinary and specialist dangerous dog advice was sought.
"Due to its continued extremely aggressive nature and risk to members of the public the dog was humanely destroyed at about 10pm."
