Spike ranks at #166 with 631 entries, and the name has been doing roughly the same job for roughly a century. It is the cartoon tough-dog name, the bulldog-of-Saturday-morning name, the affectionate-but-rough name. Almost no one picks Spike for a small fluffy lap dog, and the data backs that up.
The cartoon-tough lineage
Spike has been the default tough-dog name in American cartoons since the 1942 Tom and Jerry bulldog, and the same texture carried through Spike from Rugrats, the Buffyverse vampire, and dozens of comic-strip dogs. Owners who pick Spike are almost always playing into the cartoon archetype on purpose. The name carries a wink built in.
One counter-reading: a smaller but distinct subset of Spike owners go the opposite direction and pick the name ironically for tiny dogs — Chihuahuas, Yorkies, and small terriers named Spike are common enough that they form a recognizable secondary cluster. The irony works because the cartoon-tough texture is so legible.
The breed concentration is real
Bulldogs, mid-sized terriers, and short-coated mixed breeds carry Spike at well above the average rate. The name reads short and sharp — one syllable, hard K sound — which matches the visual-register most owners have in mind. Compare with Rocky and Bruno, which sit in adjacent tough-dog name slots.
Spike does not cross to baby naming, which is unusual at this rank because most pet leaderboard names have at least some human-chart presence. The dedicated-pet-name register keeps the slot clean and avoids the cross-pollination problem that Bella or Charlie owners sometimes run into when meeting children with the same name. Owners who like the cartoon-tough register but want a slightly less common alternative often cross-shop with Duke or Ace.