Bigsby reads like a surname that decided to skip a generation and go straight to the dog — and the fit is excellent. Three syllables with an inherent physical suggestion (big + the -sby suffix common in English surnames), it works best on dogs who are, in fact, somewhat large, or on small dogs where the size irony is the entire point.
Invented Surname Energy
Bigsby sits in the same category as Grimsby, Barnabus, and other invented-feeling surname-style pet names that have the texture of an English village without belonging to any specific geography. These names signal an owner with a specific taste for the whimsically British — think countryside aesthetics, wax jackets, dogs named after fictional earls who don't exist. Basset Hounds and Bloodhounds are natural hosts.
The Irony Potential
Bigsby on a small dog is a complete joke and also a completely good name. The -sby suffix gives it a pomposity that small dogs, in their infinite dignity, fully inhabit. On a large dog it's more straightforward — descriptive, proud, confident. Both readings work.
The Counter-Reading: Invented Names Age Differently
Bigsby has no historical anchor — it's a constructed name that sounds real. That gives it a fresh quality now but may date it more quickly than names with genuine etymology. For a similar register with historical grounding, Kingsley or Barclay cover the English-surname aesthetic with actual name histories behind them.