Especially during these short days of the year, light-up collars and leashes are great for taking your dog for that last piddle in the dark. But you may want to leave off the flash option so the bulbs don’t keep blinking. Flashing lights can bring on epileptic attacks in some people. And they may irritate some dogs, or worse, make them feel anxious or unnerved. Best to light up your dog’s night life with a steady glow.