If the dog is mixed, there's really no way to tell for certain what it is by a picture. The dog appears to be either a poodle or poodle mix, but if he's a mix you likely won't be able to tell the difference between, say, a cocker-spaniel poodle mix or other similar mixes, or if the dog is large (I can't tell from the picture) a Labrador poodle VS golden poodle or even more obscure mixes like an Australian shepherd poodle, etc.
My guess would be pure poodle or cockapoo if the dog is medium sized, and lab or golden poodle or standard poodle if it's larger.