Crossword puzzle clue "a first name in dogdom"

A first name in dogdom

Dogdom's org.

One of dogdom's "gentle giants"

First word across in the first-ever crossword (1913) and the first of a dozen appearances of the word in this puzzle's grid, written word search-style (left, right, down, and diagonally) ... Can you f

First first name?

First name of the first American in space