Do the math: On average an unspayed female dog + her mate can produce approximately 6 dozen puppies in 6 years. If none of those pups are spayed or neutered 67,000 dogs would be added to the ranks of those slated for euthanization.
Doesn’t it make sense to deal with the source of the problem before it runs rampant? A simple spay or neuter surgery can harness this uncontrolled production and eliminate the angst and expense of having to end those precious lives after the fact.