Yes, you can easily assign the tracker to another pet. All you have to do is remove the tracker from your existing pet's profile, then set it up for a new pet.
1. In the Whistle app, tap the Settings icon.
2. On the Settings screen, tap Device Details.
3. On the Device Details screen, tap Remove Device.
5. On the Remove Device message that appears, tap Remove.
6. When your old Whistle is removed, a message appears asking if you want to add a new device. Tap Dismiss.
7. On the Home page, tap the Menu icon.
8. In the menu, tap Set up New Whistle