Just to show that the term "bitch" is nothing new ...

Canicula (lit. little dog) is the Latin diminutive form of canis (dog, canine). It can also be a derogatory term typically applied to women, since it is a feminine noun of the 1st declension (suffix, -a) and is doubly so by being a dimunitive. One Latin dictionary defines it as:

canicula -ae f. (little bitch) sometimes a term of abuse. Transf. , (dog-star, Sirius; the worst throw at dice).

Canicula is also the accepted term for a female dog in Latin, and not in a canine in the general sense as in canis.