DEAR PAW’S CORNER: My little Sheltie, “Gabriel,” loves going for walks outside, but he starts shivering after about five to 10 minutes and we have to turn around and go home. He’s really active, so I don’t understand why he can’t stay warm. Can you help? -- Joseph in Grand Rapids, Michigan DEAR JOSEPH: Little dogs are bundles of energy, but that’s often not enough to defeat Mother Nature and stay …