From ANIMAL PEOPLE, July/August 2005:
The numbers of dogs and cats killed in U.S. animal shelters
appears to have resumed a 35-year decline after a brief spike upward,
according to the 12th annual ANIMAL PEOPLE review of shelter exit
data. The overall rate of shelter killing per 1,000 Americans now
stands at 15.5.
Shelter killing is coming down in all parts of the U.S., but
progress remains most apparent where low-cost and early-age dog and
cat sterilization programs started first, decades ago, followed by
aggressive neuter/return feral cat sterilization, introduced on a
large scale during the early 1990s.
Regions with harsh winters that inhibit the survival of stray
and feral kittens were usually killing more than 100 dogs and cats
per 1,000 humans circa 1970. The U.S. average was 115, and the
Southern toll (where known) soared above 250.
Current regional norms vary from 3.6 in the Northeast to 27.5
along the Gulf Coast and 29.2 in Appalachia.
The Northeast toll is as low as it is partly because most
animal control agencies in Connecticut still do not actively pick up
cats, although they were authorized to do so in 1991–but even if
Connecticut agencies collected two or three times as many cats as
dogs, the overall Northeast rate of shelter killing would be less
than 4.5 dogs and cats per 1,000 humans.