Yes, puppies grow so fast that the calcium goes to the bones more than the
cartilage in their ears, therefore causing weak ear cartilage when they are
young.Teething takes extra calcium too, which is the reason why your Chi's
ears sometimes drop. It's normal for the ears to go up and down during teething,
some days it can be one ear, some days both, usually the ears will be up
permanently by 7 months. Some Chis never go through this, others end up with
permanently floppy ears, like my Chanel for example. Try to not touch the ears
often, and give plenty to chew on in order to help strengthen that cartilage.