Henny is a diminutive with multiple origin points: it can be a shortform of Henry, Henrietta, or Henna, or a reference to Henny Youngman, the classic Borscht Belt comedian. At rank 1279 in the pet registry, it's a genuinely warm and slightly silly name that works well on small-to-medium dogs whose owners want something affectionate without going full formal.
The Nickname Name Logic
Nickname names on pets — Archie instead of Archibald, Benny instead of Benjamin, Henny instead of Henry — operate on the assumption that the casual form is the better daily-use name. On pets this is almost always true. Henny has a soft bounce to it that sits naturally in commands: "Henny, come" lands better phonetically than "Henrietta, come." Beagles and Cocker spaniels whose owners want a warm, familiar name without the full formal version are the natural home for Henny.
Henny Youngman and the Comedy Connection
"Take my wife, please" is probably the most famous one-liner in American comedy, delivered by Henny Youngman for decades. The name carries a faint comedic warmth from that association: easygoing, crowd-pleasing, never trying too hard. That energy maps well onto dogs that are fundamentally agreeable. Compare Benny for the same register without the comedy footnote.
The Counter-Reading
Henny can sound slightly old-fashioned to some ears, which is either charming or a mild drawback depending on taste. It's also occasionally used as a slang term in certain communities, so regional context matters. Generally, though, Henny is a reliable, warm choice that holds up well in daily use.