Theodore ranks at #267 with 426 entries, and it sits at the dignified peak of the vintage-revival cohort. The full-form formality, almost always paired with a casual nickname like Teddy or Theo in daily use, is the entire selling point.
The full-name-with-nickname pattern
Theodore on the registration form, Teddy at the door — that is the modern naming pattern, and it shows up across Oliver, Winston, and Franklin too. Owners want the gravitas of the full name on paper and the affection of the short form in real life. Theodore is the cleanest example because Teddy is one of the warmest pet nicknames in English.
Where Theodore lands
Small fluffy breeds carry the name at the highest rates: Cavaliers, Bichons, Poodle mixes, and small doodles. The fluff visually echoes the teddy-bear association, which is part of why the name has migrated so heavily to that breed segment. Two- and three-syllable shapes (THEE-uh-dor) work fine because owners rarely call the full form anyway.
The presidential counter-reading
One reading worth noting: Theodore Roosevelt gave the teddy bear its name after the 1902 hunting trip story, which means every Teddy on a fluffy dog is downstream of that single cultural moment. Most owners do not consciously engage with that, but the lineage is unusually direct. The Theodore baby name page shows it climbed sharply on the SSA chart through the 2010s.