Police are investigating after the attack on Dalston Road in Carlisle at approximately 7:45pm on Friday, April 10.
A 27-year-old man, from Carlisle, sustained wounds to his leg from the dog.
The dog was believed to be a crossbreed which was black in colour and was possibly a Doberman.
The owner of the dog was said to be a white man, believed to be in his 40s or 50s, wearing yellow wellies, green jacket and black trousers, police said.
Police are appealing for witnesses for this incident.
Anyone with information relating to this incident can report online at www.cumbria.police.uk/report-it, quoting incident number 209 of the 10 April. You can also phone on 101.
Alternatively, you can contact Crimestoppers, anonymously, on 0800 555 111.
