While our historic milestone provides plenty of reasons to take pause and commemorate our past, the urgency of our cause demands that we continue to look ahead. To that end, the ASPCA is at the forefront of three relatively new areas of animal welfare concentration where the potential for saving lives is nearly limitless.

After I got married and had two kids of my own, I vowed that I would give them the pet experience I never had. We adopted a dog -- an irresistible floppy-eared basset hound named Darwin -- soon followed by cats, each lovable in its own disdainful way.

While some reasonable estimates exist, the true number of U.S. animals sheltered at a national level has never actually been counted, much less shared. This lack of clarity severely impedes our ability to best serve our country's homeless animals.

One of the most telling discoveries from the study was that people with incomes below $50,000 were significantly more likely than their wealthier counterparts to re-home animals due to cost and housing issues. They were also more likely to re-home all pets in the household at once.