Are you looking for picture of pet -> 2D asset or picture of pet -> 3D model of pet?
2D asset from 2D picture is easy and built into both Unity and Unreal.
3D asset from many 2D pictures of a stationary object is available, eg Luma AI.
3D asset from single 2D picture is something Meta Labs (and others) has done tons of work on and is undoubtedly a core part of their VR plans, but not readily available at high quality today commercially and automatically (to the best of my knowledge).