The Puzzling Geography of Animal Shelter Dog Euthanasia

A new study examines the cruel geography of deaths in animal shelters.

Posted May 11, 2018

Photo by fotojagodka/123rf
Source: Photo by fotojagodka/123rf

In 1973, there were 65 million pet dogs and cats in the United States, and 20% of this number were put to death in animal shelters. Today, there are 160 million pet dogs and cats but less than 2% of that number is euthanized in shelters. In a recent article in the journal Animals, Andrew Rowan and Tamara Kartal examine the reasons for this 90% drop and raise an intriguing and important question: Why does geography determine whether a shelter dog will be euthanized?

The Big Drop in Animal Shelter Dog and Cat Deaths

As shown in the graph above, the rates of unwanted pet euthanasia per 1,000 people has dropped precipitously. Rowan and Kartal attribute this impressive decline in shelter animal deaths to several factors. In 1970s, groups such as the Humane Society of the United States, the American Humane Association, and the American Veterinary Medical Association made the pet overpopulation crisis a high profile national issue. As the spay and neuter movement became a moral crusade, cities and states began to establish low-cost sterilization programs and enact mandatory dog licensing regulations. Presently, 32 states require that dogs adopted from a shelter be sterilized, and the percentage of American dogs that are spayed or neutered has increased from 10% to nearly 85%.

A second factor for the fall in shelter deaths dates to the early 2000s, when the numbers of dogs and cats successfully adopted from shelters began to rise. This trend was, in part, due to the efforts of animal protection organizations to encourage people seeking a pet to adopt a dog or cat from an animal shelter rather than purchasing a companion animal from a pet store. PETA, for example, equated buying a purebred puppy with killing a shelter dog. (About the same time, American Kennel Club pedigree puppy registrations began to tank.) Finally, Rowan and Kartal note that there has been a major cultural shift in how Americans think about animals. A large majority of owners now thinks of dogs and cats as family members. This trend toward the humanization of pets has resulted in more adoptions and fewer deaths of healthy animals in shelters.

Graph by Hal Herzog
Source: Graph by Hal Herzog

Is Geography Destiny? 

While the drop in deaths is impressive, the odds that a dog or cat will survive a stint in an animal shelter depend on where it lives. Rowan and Kartal obtained rates of canine shelter deaths in eleven states. This graph shows the number of dogs killed per 1,000 people in each state. In my state, North Carolina, a healthy dog in an animal shelter is nearly 25 times more likely to be euthanized than a dog in New Hampshire. It would be easy to assume that this is simply due to regional differences in attitudes toward animals. That theory, however, does not explain why a North Carolina dog is three times more likely to die in shelter than a dog in the neighboring state of Virginia. Nor does it explain why California, one of the most progressive states, has a dog euthanasia rate three and half times greater than Colorado.

I emailed Rowan for his take on geographic differences in shelter dog deaths. He wrote back:

The state-by-state issues have been obvious for decades but nobody has paid any attention to them. There are huge differences within states, too. For example, Fresno County in California has a euthanasia rate of 35 per 1,000 whereas San Francisco’s is 1 or lower. If you look at expenditures, Fresno’s is around $15 per capita and San Francisco’s was around $30 per capita. But the five counties around Portland spend around $16 per capita and have a euthanasia rate one tenth that of Fresno. People have suggested that Fresno tends to be lower income (the interior counties in California have higher euthanasia rates than the coastal counties) and that may be an explanatory factor.

Graph by Hal Herzog
Source: Graph by Hal Herzog

Curious, I ran a few statistics. This scatterplot shows the relationships between the per capita income of the 11 states and their rates of shelter dog euthanasia. The downward slope of the regression line indicates that the relationship is negative. This means states with lower average incomes tended to kill more animals in shelters. (For stat geeks, r = .65.) This is a substantial relationship. For reasons I won’t trouble you with, this finding means that about 40% of the between-state differences in dog euthanasia was associated with differences in income. 

But other factors could also be involved—for example, attitudes toward government regulations. Perhaps more people in the South don’t like restrictions on the sex lives of their pets any more than they like zoning or gun laws. To test this hypothesis, I looked at the relationship between differences between states in shelter dog deaths and in gun ownership rates. The relationship between dog deaths and gun ownership was not as high as with income (r = .44) and was in the opposite direction: States with higher rates of gun ownership had more dog deaths.

The Scandinavian Paradox

The same kinds of large geographic differences in healthy pet deaths also exist between countries. In the US, the overall rate of shelter euthanasia is 5.6 per 1,000 people. But in the UK, the rate is 0.2. And in Sweden, it is close to zero despite the fact that only 20% of Swedish dogs are neutered. This is less than a fourth of the pet sterilization rate in the United States. Neither does Norway have an unwanted pet problem even though routine castration of dogs is not permitted under their Animal Welfare Act. (Neutering is allowed for medical reasons.)

Puzzled by this “Scandinavian Paradox,” I turned to Dr. Peter Sandøe, a bioethicist at the University of Copenhagen. He explained why countries with such low spay and neuter rates have hardly any problems with unwanted dogs. First, he said, there are simply fewer dogs in these nations. For example, 20% of Danish households include a dog, compared to 36% of US homes. Second, Scandinavian countries have strict laws dictating that dogs be under their owners’ control at all times, and dogs are not allowed to roam freely. Finally, he attributes the low euthanasia rates to the fact that Scandinavians have a generally law-abiding culture. 

Unwanted Pet Euthanasia and Moral Progress

On the morning of July 5, 1877, a large crowd of New Yorkers gathered on the banks of the East River to watch the authorities drown stray dogs. Forty-eight animals at a time were crammed into a heavy iron cage dubbed “the canine bath tub.” Then the cage was slowly lowered into the river. After ten minutes, the cage was raised, the corpses removed, and cage reloaded. According to The New York Times, 762 dogs were killed that day. 

Animal protectionists can take heart in knowing we have come a long way since the days when unwanted dogs and cats were drowned en masse. The decline in euthanasia of animals in the United States from nearly 15 million a years to fewer than 3 million represents considerable moral progress. Indeed, I believe it is the single biggest success of the modern animal protection movement. Even today in the United States, however, dogs and cats in shelters are put to death at a rate of six animals every minute. There is plenty of room for improvement.


Rowan, A., & Kartal, T. (2018). Dog population and dog sheltering trends in the United States of America. Animals: 8(5).