Are you worried if Fido’s getting enough exercise? Whistle is here to help you out. Whistle is a new gadget that attaches to your dog’s collar and tracks its activity levels, just like Fitbit does for humans. Whistle is more than a silly gadget, though. Veterinarians say dogs are easily able to hide symptoms or illnesses from their owners, and even sick animals can appear healthy at vets thanks to adrenaline and a desire to show off. Whistle tracks your dog’s activity when it’s in its normal habitat. Making use of an accelerometer, Whistle tracks whether your dog is walking, playing or sleeping, and measures daily activity and changes in exercise. If it notices a sudden change, it will let you know via the free companion mobile app, which you can share with your vet. Selling for $99, Whistle will help make sure your dogs get enough exercise on a daily basis and live the long and healthy lives they were meant to live.