The horse thing above reminded me that twice in the last freezes, a Fire Department had to be called to rescue people's dogs from falling through the ice. If it happens, a ladder slid out on the ice to the hole helps to distribute the weight of the rescuer.
And if the 50 lb dog went through, what'll happen to the 200 lb you?
(And from personal scary experience, most ponds have thick icky bottoms which make it very difficult to get out of. This is true regardless of the weather.)
Terry