I have two GSPs, absolutely worthless for hunting, but aesthetically GSPs. They live out at #3 son's place. Their job is to bark when someone drives in the gate and keep barking until they leave (at least I think they stop when I leave). They belonged to my father. It's next to impossible for an 80 year old guy to properly train TWO GSPs to do anything. One of them is a biscuit eater and the other one might do well at the dog track if they'd replace the rabbit with a chicken...
I've had experience with Labs, GSPs, Chessies, English Pointers, and Irish Setters. The dog in the picture doesn't look like anything I've seen before.
A Google image search brought up "ratonero bodeguero andaluz" which clearly it is not a rat terrier.
Whatever it is, being staked out in the mud probably isn't enhancing it's skill set any...
Alan