prison, kind of wild dog
豻 centers on a wild canine, specifically a kind of wild dog, and by extension a prison, likely from the idea of a cage or confinement associated with such an animal.
豻 combines the beast radical 豸 with 干, which likely served as a phonetic component. The character originally referred to a type of wild dog, and the prison meaning may derive from the idea of a cage or confinement.
A wild beast (豸) with a shield (干) — imagine a fierce wild dog guarding a prison, its cage-like den.
For カン, picture a can (カン) being used as a makeshift cage for the wild dog: can -> カン, and the beast is trapped inside.
—