A
B
C
D
The dog in photograph B is the offspring of photograph A.

The puppy in photograph C is also the offspring of
photograph A from a recent litter.

The puppy in photograph D is the offspring of photograph B.

Both mother and offspring gave birth within days of each
other.  The adults dogs were spayed and returned to their
owner.  The puppies were removed from the site.
Junkyard - Brownsville, Brooklyn