Decades ago when I walked the lower depths of the demi-monde, I met a man who raised and sold Dalmatians for purposes of bestiality. He informed me that the breed was considered best for intercourse with human females. Endowment, stamina, and trainability were all factors that he felt favored that particular dog.
He said it was a well known fact among practioners of bestiality that Dalmatians were superior. I must say it was not well known to me.
He invited me to his kennel where I met his wife and daughter who helped train the dogs. Must to my pleasant surrpise, they asked me to participate in a training session. I enjoyed my first (and last) multi-species sexual encounter.
My host only trained male dogs for sale to human females but informed me that there were several major breeders in Germany who offered well-trained female German Shepherds for sale to human males.

Personally, I do not find bestiality of sufficient interest to pursue. I would think it might be difficult to knit it into a BDSM lifestyle.