Pretty familiar, I also use it for prototyping. It's an awesome material, but FDM is no match for a dogs teeth.

I wouldn't want to take the risk, peraonally, but I guess it comes down to your level of risk tolerance and if you're absolutely confident it won't harm your pet

I'd be very concerned about the dog toys breaking apart and causing the dog harm.

I think non-used prototypes would be fine, but nothing that would actually go near the dog