expression, ichidan verb
to be betrayed by a trusted follower
Idiomatic expression literally meaning 'to have one's hand bitten by one's own dog'. Used when someone you trust or have cared for turns against you.
長年面倒を見てきた後輩に裏切られて、まさに飼い犬に手を噛まれる思いだ。
Being betrayed by a junior colleague I had looked after for years, it really feels like being bitten by my own dog.