These new 'dogverts' are sprayed onto the coats of dogs using vegetable dye and then when the dog is taken out for a walk everyone sees the advert.
Computer game producers THQ are behind the plan, and are using it promote a new game they have made for the PlayStation 2.
Dye comes off in the wash
They tested the ad out on a golden Labrador called Fido in a London park, and it was a great success.
Loads of people stopped to look at the dog and after Fido had been walked and washed all the dye - and mud - came off with normal dog shampoo.