A three-year-old Huddersfield boy needed stitches after being bitten by a pitbull-type dog roaming loose in the street.
The boy and his father were walking in Elmwood Close, Highfields, at 11.30am on Saturday when two dogs came bounding towards them.
The little boy became scared and the dad, who has asked not be named, picked his son up.
However, one of the dogs jumped up at him, biting the boy’s left calf.
The youngster was taken to Bradford Royal Infirmary for specialist treatment. He was released after having stitches inserted in the wound.
A 21-year-old Huddersfield man was later arrested on suspicion of an offence under the Dangerous Dogs Act 1991.
He is accused of being the owner or person responsible for a dog dangerously out of control. The man remained in police custody.
Police have also seized a dog and tests will be carried out to determine whether it is a breed banned under the Dangerous Dogs Act.
Det Insp Ian Thornes, of Huddersfield CID, appealed for witnesses to the attack and said: “It was a terrifying experience for this little boy and his dad and inquiries are underway.
“The dog bit the child through his clothing and then both dogs ran off. The dog concerned is a Staffie or pitbull type and we are working with the RSPCA to find out whether it comes under the Dangerous Dogs Act.
“We take incidents such as this very seriously and a full investigation will be carried out.”
The boy is now recovering from his ordeal at home.
Anyone with information on the attack should contact Det Con Jo Sharp, at Huddersfield CID, on 101 or via Crimestoppers, anonymously, on 0800 555 111.