The victim was with his dog, Zen, in Bitts Park, Carlisle, Cumbria, when he was assaulted by a man at about 12.30am on 16 October 2023.
Zen is a two-year-old female Labrador and Staffordshire bull terrier cross – became separated from him during the incident and it is unclear if Zen ran away or was stolen.
As part of enquiries into the incident, police are asking for anyone who see Zen to get in touch.
The man who carried out the assault was white and about 30 and was with a woman who was white and about 18.
Zen is described as being golden brown with dark patches on her head and tail.
She had on a yellow collar with a handle on it and a tag with the name Zen on it.
If anyone has any information they can call police on 101, referring to incident 23 of October 16. Or contact Crime Stoppers anonymously on 0800555111
Advised to register on Doglost.co.uk and receive the help from their Police liaison Team