It seems to be a trench art ring. It is almost impossible to say is it original or not but it seems pretty OK to me. So if the price is good, buy it.
Detail looks very poor to me, unless its extremely cheap and therefore worth taking a risk on, I wouldn't bother. More photos would certainly help but from this one shot i'm not a believer.
I can say the dog is definitely real. A mini or full size? The ring who knows.
I like your dog.
I wouldn't buy it or anything from Ioffer, as this is where pretty much all the fake and fantasy Third Reich items are being sold from!
A crudely(intentionally so) made fake. This style of fake rings have been showing up more and more of late. Apparently, there's been some sort of strategy shift with the fakers-rather than continue on with the high quality detailed fakes that can usually be proven, they are changing over to these "hand made trench art style" things that have no standards of mass production. When they pre-age them, who is to know,hey?
"Much that once was, is lost. For none now live who remember it."