Trends in intake and outcome data for animal shelters in a large U.S. Metropolitan area, 1989 to 2010.

Trends in nonhuman animal shelter intake and outcomes for dogs and cats in Metro Denver, CO, between 1989 and 2010 were assessed by linear regression analyses of data from 4 of the largest facilities covering 3 counties. The data were analyzed for trends on 3 scales: actual numbers per year, number per 1,000 residents per year, and as a percentage of total intake. Approximately 21,000 dogs and 16,000 cats were taken into the shelters in 2010, representing a 24% decrease for each since 1989. For dogs on a per-1,000-residents basis, intake decreased by 44%, euthanasia by 77%, and adoption by 13%; the live release rate (LRR) increased by 39%. For cats on the same scale, there was a 53% decrease in intake until 1998 followed by an 11% increase through 2010, and an 82% decrease in euthanasia until 2000 followed by a 24% increase through 2010. Adoption of cats per 1,000 residents remained unchanged, but the overall LRR for cats doubled during the study period. Substantially increasing trends in the transfer of dogs and cats from shelters to rescue organizations reflect efforts to optimize adoptions.