Ball balancing

Good evening, Robin here: Here's a picture of Mom helping Zeeba learn to balance on the big ball he won at Dog Daz. It's supposed to be good for his core muscles, and I thought that only apples had cores.
I've been swimming in our pond ever since the ice went out, but today was the first day that Mom came in swimming with me. Zeeba still will only swim if somebody carries him into the water. He likes to wade--but swim---No way!! Dad says that he's the first non-swimming sheltie we've had.