Pet dogs produce a larger volume of tears when they are reunited with their owners than with acquaintances, possibly because of surging oxytocin levels—findings that could be the first evidence of emotional crying in nonhuman animals.

Pet dogs produce a larger volume of tears when they are reunited with their owners than with acquaintances, possibly because of surging oxytocin levels—findings that could be the first evidence of emotional crying in nonhuman animals.