Study: Number of dogs in shelters at all-time low?February 16, 2017A new study found that the number of dogs in U.S. shelters might be at an all-time low. That’s thanks to researchers from the Mississippi University College of Veterinary Medicine, who used survey data and capture-recapture methodology to determine the number of dogs in U.S. animal shelters, as well as adoption rates, transfer rates and euthanasia rates.