My Grandma told me a similar story. She grew up in a small village in the Czech Republic and there were rumors going around that the wife of the mayor had sex with their German Sheppard whenever her husband was on a business trip. One day he came back home earlier and caught his wife and his dog in the act... and killed them both with his rifle.
It sickens me that in the 21st century people are still doing such disgusting things... Come on, if she is that desperate she could have bought herself an inflatable love doll with a giant penis or whatever. Maybe they even sell inflatable dogs for such sickos so there is no need to use a real animal.
When you come to think of it, that is even cruelty to animals.