They’re both called “Spot”!
The name “Cerberus” is a Latinised version of the Greek Kerberos. The etymology of this name prior to Greek is disputed. It has been claimed to be related to the Sanskrit word सर्वरा sarvarā, used as an epithet of one of the dogs of Yama, from a Proto-Indo-European word *k̑érberos, meaning “spotted” [wikipedia]
For all my social networking posts, see my Google+ page