-- out of the tail and a fascinating new study on man's best friend. What turns out -- tail -- means a lot more than just a happy puppy our Sara Haines is here with all the details I've been curious... See More
-- out of the tail and a fascinating new study on man's best friend. What turns out -- tail -- means a lot more than just a happy puppy our Sara Haines is here with all the details I've been curious about this for years now I'm glad you finally. I don't know we have a lot of clear finding answers here as a dog owner I know when my -- are happy and a wagging tail is a good indicator but he is not that not. -- tail wags are created equally. Did you know that the -- dogs wag your tail can be -- telltale sign of how your furry friend is -- It's -- recently a group of Italian researchers discovered dogs can read how another dog feels. Just from the wagging up its -- became even beat contagious. Dollars and research group showed increased heart rates while watching other dogs -- their -- to the left. And remained home while watching other dogs -- their -- to the right. Good god -- New York City dog trainer and -- to gag non -- it was about dogs teen -- it. It's a dog died they -- things that we don't tax. That says there -- their -- of -- had to think that we don't catch. -- -- to research from 2007. That if the dog wags its tail to the left it's like peeling paint us. And right -- and relax he decided to head to the park to sniff out some other -- body language reading -- -- here. The tale I've seen this little -- move a couple times -- here how. Without -- -- how can you -- yet you have no idea come I just have to assume he's happy looks happy. It. The -- to communicating a -- all the time with all of their body language. You tell my client look at the overall picture of their. From nineteen canine babies Peter in -- C one -- fresher. Peter doesn't care for the -- to deface. It if -- Nobody -- the details I think -- them. Yet it -- not that overall thing I learned from the behaviors is it's really about the whole picture you don't want to hone in on one thing whether it's a Baring teeth or. It's the whole -- yeah I -- I don't. Harry yeah.
This transcript has been automatically generated and may not be 100% accurate.