Jackie, I'd disagree with you on this, and think "hog" means the mature animal, of either gender.

BUT: bartleby-ing indicates that:
-hog can either mean (1a) the animal, whether domesticated or the wild, or (1b) the domesticated animal, but especially one weighing over 54 kilograms (120 pounds)
-boar can either mean the adult male, or the uncastrated male, or the wild boar.
-pig means a member of this biological family, but "especially the domesticated hog ... when young or of comparatively small size."

Ogden Nash claims a different distinction between pig and hog:
Why does the pygmy
Indulge in polygmy?
His tribal dogma
Frowns on monogma.
Monogma's a stigma
To any pigma:
If he goes for monogmy
A pygmy's a hogmy.