Yes, DASSIES is a Scrabble word!

Letter values in Scrabble US: D 2, A 1, S 1, S 1, I 1, E 1, S 1.

Is it a valid word?

DASSIES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any of several small ungulate mammals of Africa and Asia with rodent-like incisors and feet with hooflike toes

Not playable in Scrabble US: DAS.