puppy with out tail

Question
I have a spits and a terrier mix that just had puppys with another terrier and she has one puppy that was born with out a tail. He doesnt even have a spot that looked like he was ever going to get one so i was wondering what type of dog this coulds be and if he could possibly be some rare type.

Answer
Hello, Well you are saying you had a Spritz X terrier and she was bred by a terrier correct? What type of terriers are involved here? Boston terriers are Born without tails jack russell terriers tails are Docked.... Schipperkes also have no tail and i think they are born without them these are a type of small spritz dog...if you could let me know the type of terriers involved (the cross half and the other pure terrier). Since the two dogs bred together  = a litter of mutt puppies the tailless puppy isnt considered rare because its not a purebred and genrally couldn't be sold for more if that is what was implyed? I need to know the exact breeds to be able to figure out why one had no tail.