It doesn't sound as cute as "puppy," but whelp means the same thing: a baby dog or wolf. This can also be a verb, as in "The mama poodle whelped six whelps."
To someone who studies animals, whelp is just the word for a newborn dog or for birthing. Besides applying to canines such as wolves and coyotes, whelp is sometimes used to describe a young person. This usually isn't a compliment. If an older person calls a young person a whelp or says, "I don't know what's wrong with you whelps these days!", you can be sure they're not impressed by youngsters.