The incident happened on a bus in Sturry Road, Canterbury at around 7.40pm on Saturday 10 August 2024.
The dog is described as a black or brown Staffordshire terrier-type. The girl suffered cuts, which are not believed to be serious.
Enquiries into the incident are ongoing and police have released an image of a man who may be able to assist the investigation.
Anyone with information, or who recognises the man, is urged to call Kent Police on 01843 222289 quoting reference 46/134407/24.
You can also contact Crimestoppers anonymously by calling 0800 555111 or complete their online form.
