It may be used technically (like between dog breeders) but I believe the average american would use "dog" when referring to his female dog in casual conversation.
I agree, though, that when translating a language that differentiates between male and female, it would make sense to give credit when the correct gender terminology is used.
Worth adding that English swear words also mean the same in Hebrew (though are viewed somewhat less offensively from what I understand, and take on Hebrew endings at least in plural form, so multiple bitches, is bitchiot... And I've only ever heard that in terms of the profanity, unsure about dog breeders) So in the case of bitch, well, it's still understood as a profanity in Israel as well.
Well, if ב is the first letter of a string of letters (the beginning, if you want), it is always the plosive [b]. If it comes last, it is [v]. If it is in the Middle, both are possible, the rules are complex. As a first rule of thumb I would say, if ב follows a closed syllable, it is usually (but not always) the plosive [b], like here [kal-ba...]
I have a trick that works for me: instead of trying to memorize rules I made an assumption that initially letter "bet" was representing a sound in between "b" and "v". While reading I pronounce it always as "bv" and more than often accurate pronunciation is the result of interaction with the sounds before and after it. Let me know if that works for you :-)