we have a 15-yr old Shih Tzu. She's in reasonably good health. no meds, eats well, pees & poops ok. recently had vet visit. heart & breathing ok. lately, this hot-ish summer, she seems to have developed like a nose / breathing issue... she making noises that sound like someone with runny nose or cold makes when the have the sniffles. seems to be when she breathes in, not out. like someone stopping a runny nose. not all the time, but little bouts of it. her nostrils are usually dry, but sometimes a little discharge. and she sometimes gets a little green-ish cast on her nose, which we wipe away with a warm cloth. Anyone have any experience with this or something similar, beforevwe head back to the vet?