When I brought Alfie home from the vets, he was so doppy from the anaesthetic that he banged the cone of shame on the tarmac with every step that he took, spooking himself. Having carried him into the house, he then proceeded to bang the cone into furniture and door frames.
The vet will usually loan or charge for an Elizabethan collar, also known as E-Collar, or pet cone, sometimes humorously called a pet lamp-shade, pet radar dish or cone of shame.
I've used it on both my dogs, and am really glad that I bought the Comfy collar. I put it on them in a horse shoe shape, which allows the dog to sleep on its back without discomfort.