It is possible to delete or disable animals. You can access the options in the animal details page and select the option in the hamburger menu.
Delete an animal - When you delete an animal, the animal and all its history, files and related content will also be removed from your account. There is no way to recover this information.
Disabling an animal - When you disable an animal, all its history, files and related content will remain intact and will still be accessible when you need it. The animal will not be shown anymore in the overview and all selection boxes where you can browse through your active animals. You also can't add any information or files to it anymore. In order to see the information of the animal, change the appropriate filter option on the overview page.