I think it would be slightly odd if there were an 'industry standard' for this one. Even odder if the general speaking / writing public both knew of that standard and actually used it.
As noted in a comment against OP, you can't check this one with Ngrams because that doesn't support the slash character in search terms.
But you can Google for
"b/w" movies
which reports 6,650,000 hits, and
"b&w" movies
which reports 4,570,000.
If I add the word american I get 2,960,000 as against 2,310,000. That's much the same ratio, which may imply there're no particular tendency for Americans to favour one term over the other.
I can't restrict Google to US sites only, but I can restrict it to UK only. That gives twice as many hits for b/w, which may suggest that we Brits prefer the slash form. I know I do.
While raise is used for animals, it is usually in an agricultural setting. You are right to think it sounds unusual to speak of raising a household pet such as a dog or cat. It is much more common for someone to say that they have or that they own a dog. If one raises an animal, or animals, it is almost always for a specific purpose (other than companionship) such as meat production or breeding.
What this says about our use of raise for children, I'm not quite sure.
Best Answer
They are both correct, but the word guess is used in different senses:
The examples given are more enlightening than the definitions; you see that the usage of guess is correct either like this:
or like this: