"You have heard that it was said, 'You shall not commit adultery.' But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart. If your right eye causes you to sin, tear it out and throw it away. For it is better...
And the Hadith actually proves that sex with animals is a sin, but there is no specific punishment (ex: 100 lashes) for it. The punishment FOR THIS SIN is open depending on the case and the type of sin. The only mate for man is the woman: [039:006] He created you from one ...