Disturbing footage has been released by the RSPCA of a man repeatedly punching a "clearly petrified" dog in the street.
The video, filmed by a member of the public in Lancashire, has led to serious concerns for the dog's welfare.
The attack occurred on Hendon Road in Nelson, at about 3.15pm, on December 10.
RSPCA Inspector Charlotte Booker said the dog, who appears to be an American bulldog, was "clearly petrified".
She said: "This is an urgent appeal to find the man in the footage, which we are releasing today, and the dog, whose welfare we are extremely concerned about.
"We hope that the images of him and the dog - a large white bull breed, we think probably an American bulldog - along with the location and time this happened will mean that those who know him will recognise him, and call us."
The RSPCA inspector added: "This was a sustained attack on a dog which was clearly petrified and submissive and which had to be picked up and carried down the street afterwards.
"Please, if you have any specific information about this man, and where the dog is now, get in touch."
Anyone with information is urged to call the RSPCA on 0300 123 8018.