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I got my JRT puppy March 3rd; he'll be 12 wks old on the 19th. He's happy, healthy, smart & quiet--too quiet! I've heard him whine, yelp (cat got too rough with him) & play growl, but he's never, ever barked. Even when my Lab barks, Gage is quiet. Should I be concerned? His hearing is fine; he knows his name and is 95% potty trained. My daughter has a 2 yr old JRT & he's extemely vocal--always has been. The lack of bark is bothering me.