At about 6.30pm on Friday, June 26, the young boy and his father were cycling along a bridleway from Manor Farm, Upton, to Langley Bush Road, Marholm, when a dog ran over and bit the child on the thigh causing swelling and bruising.
The dog was being walked by two women and was off the lead at the time. It’s described as a large, black, broad chested dog.
PC Kimberley Whelan, who is investigating, said: "This was a scary experience for the victim and his dad and left both of them quite shaken.
"We’d like to speak to the women walking the dog or anyone who witnessed the incident so we can ensure this sort of thing doesn’t happen again."
Anyone with any information should call police on 101, quoting crime reference number 35/41924/20 or visit www.cambs.police.uk/report. Alternatively, contact Crimestoppers, anonymously, on 0800 555111 or via www.crimestoppers-uk.org.