A black Labrador wagging its tail
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Scientists decipher dog-tail wags

1 November 2013 Last updated at 14:27 GMT

Scientists have shed more light on how the movements of a dog's tail are linked to its mood.

Earlier research had revealed that happy dogs wag their tails more to the right (from the dog's point of view), while nervous dogs have a left-dominated swish.

But now scientists say that fellow canines can spot and respond to these subtle tail differences.

Robert Hall reports.