At 16 weeks your baby is still teething and more the likely this is the reason the ears are down. This happened to Tigger and I did exactly what you are doing now, but I gave it some time and They are now back to normal and standing perfectly erect. There's nothing wrong, Don't tape them right now. Give them a few weeks and if you don't see any improvement talk to an experienced breeder, groomer or vet. I'd suggest going to the vet first and then the breeder. best of luck |