"...[T]he transport of animals goes far beyond emergency response.

"In 2018, the ASPCA reports that they relocated over 40,000 animals from areas of “high homeless pet overpopulation” to “areas with a higher demand for adoptable dogs”. Although our data represents only a snapshot in time, we can get an idea of where, geographically, these areas may be."
https://pudding.cool/2019/10/shelters/