Oof, the sheer entitlement is definitely strong with this one!
Let's break this down into a list of problems, shall we?
1) Bestiality is illegal in almost every place in the world. What benefit is it to the owner of said dog to let some random stranger on the internet fuck their dog?
2) If caught by law enforcement often the person is arrested and will often serve jailtime/imprisonment. While the animal is often killed, put down, euthanized... whatever terms work best for you.
3) Most people that have animals consider them loved ones, family members, and/or even love partners. Not some dildo for you to use.
4) Even if you find someone that is willing to share their animal partner with you, do you honestly expect them to do so without anything in return? Without them at the very freaking least watching the action? Or, without establishing a long term friendly relationship with you?
5) You literally haven't even joined 5 days ago, and you're already whining that you can't find someone that will share their animals with you. ^See issues with that above^