Customer Service (Gisele) was very helpful with sizing. After MANY times measuring and A LOT of back and forth emails with Gisele I finally settled on the xsmall and they fit my dog perfectly and are good quality.
If you’re stuck deciding on xsmall or small, here are my dogs measurements for comparison: head circumference - snug measurement at 9 3/4” and a relaxed measurement of 10”; muzzle circumference of 6”. I was concerned that the xsmall would not allow room at the sides of her eyes and there was plenty of room! The distance between the OUTSIDE corners of my dogs eyes are 3” and there is about 1/2” clearance from the corners of her eyes to the foam edge. She’s mostly poodle with some chihuahua and almost 10.5 lbs.
Took about 3 days for my dog to get used to them with the clear lens (photos attached with clear lens and stickers before I removed them). I kept her on the clear lens for about a week then to the smoke lens for a couple of weeks and now to the blue lens. My girl is 17 yrs old with diminished vision and bright sunlight has become a problem for her. These goggles have helped tremendously and she’s quite content wearing them.
One additional mention…While your dog is getting used to the googles, they may try to ‘rub’ them off their face. The lenses scratch easily so if you don’t want to see your dog wearing lenses that are scratched, consider purchasing an additional lens that your dog may wear regularly. After they get used to them. My dog slightly scratched the side of her clear lenses against the base of a light pole, trying to ‘rub’ them off, during her training phase. She’s graduated to her darker blue lens and is now used to the googles that scratching the lens is not an issue.