Green’s Dictionary of Slang

1. (US black) hard, mean, thoughtless.

1980

E. Folb Runnin’ Down Some Lines 186: It’s a doggy, doggy world out there.

2. (also doggie) obsessed with sex, lecherous (cf. doggish under dog n.² ).

1922		‘J.H. Ross’ Mint (1955) 109: Some make a boast of vice, to cover innocence. It has a doggy sound.
1924		O.O. McIntyre New York Day by Day 25 Dec. [synd. col.] Slangy show girls. And doggy blades.
1936		J.M. Armstrong Legion of Hell 31: A very ‘doggie’ feeling suddenly took possession of me. [...] I put my finger under her chin, tilted her face back, and kissed her heartily on the lips.
1975		J. Carr Bad (1995) 44: Maynard was the doggie daddy, master of the homos.

3. somewhat overly enthusiastic.

1984

Partridge DSUE (8th edn) 325/1: 1934.