Animal Overpopulation USA Facts and Figures

Animal overpopulation is a major problem in the United States. Almost 70 million animals enter shelters and 3 million of those animals are adopted into new homes.

As for the other 66 million, about 10-15% of these animals are euthanized because there simply isn’t enough room in shelters to house them all.

Left out of these statistics are the staggering number of animals that die on American streets every day from starvation, illness, or being hit by cars.

Animal overpopulation is a huge problem in the United States. There are many factors that contribute to this issue.

The biggest one is that many people don’t spay or neuter their pets. In fact, only 25% of dogs and cats are altered.

This means 75% of the country’s population consists of an unplanned litter. Another cause is irresponsible pet owners who do not pick up after their animals.

Animal feces attracts rodents and other wild animals who can then transmit diseases to humans or other animals.

Our next bullet point discusses how climate change impacts animal populations in the U.S.

As we know, a warming climate could cause an increase in populations in some countries while decreasing populations in others due to changes in food availability, vegetation growth rates, and more extreme weather events such as storms and droughts.

These changes will likely affect animal populations within the U.S., although we’re still researching how exactly these changes will happen as well as what effects they’ll have on ecosystems and animal welfare

pet Populations Facts (Birth, Death, Shelters And More)

• Number of cats and dogs born every day in the U.S.: 70,000 (nearly 3,000 borns every hour or 50 born every minute) 

• Number of stray cats and dogs living in the U.S.: 70 million

• Number of animals in the U.S. that die each year from cruelty, neglect, and exploitation: 30 million

• Number of animal shelters in the U.S.: 4,000 – 6,000

• Number of cats and dogs entering U.S. shelters each year: 6 – 8 million

• Number of cats and dogs euthanized by U.S. shelters each year: 3 – 4 million (nearly 10,000 animals killed every day)

• Number of cats and dogs adopted by U.S. shelters each year: 3 – 4 million

• Number of cats and dogs reclaimed by owners from U. S. shelters each year: 600,000-750,000 (10% of total entering shelters – 15–30% of dogs and 2–5% of cats)

• Yearly cost to U.S. taxpayers to impound, shelter, euthanize and dispose of homeless animals: $2 billion

• Percentage of dogs in U.S. shelters that are purebred: 25 – 30 %

• Average age of animals entering U.S. shelters: under 18 months old 

• Percentage of animals entering U.S. shelters that are healthy and adoptable: 90% 

• Percentage of owned dogs that were adopted from an animal shelter: 18%

• Percentage of owned cats that were adopted from an animal shelter: 16% 

• Percentage of animals entering animal shelters by animal control authorities: 42.5%

• Percentage of animals entering animal shelters that were surrendered by their owners: 30% 

• Percentage of people who acquire animals that end up giving them away, abandoning them, or taking them to shelters: 70%

• Percentage of animals surrendered to an animal shelter that was originally adopted from an animal shelter: 20% 

• Percentage of animals received by animal shelters that have been spayed or neutered: 10%


On average 25% of owned pets have not been spayed or neutered (dog owners 34%; and cat owners 15%). 

When surveyed about why pet owners have not spayed or neutered their pet, their reasons included:

• Not bothered to do it yet: 29%
• Desire to breed their animal: 16%
• Feeling that the animal was too young: 15%
• Affordability: 9%
• Feeling that it is cruel to the animal: 5%
• Feeling that it is unnatural: 4%
• Other: 15%
• Not sure: 7%

When surveyed where pet owners obtained their pets. The following sources were listed:

• Family member, friend, or neighbor: 42% 
• Animal Shelter: 15% 
• Breeder: 15% 
• Found animal as stray: 14% 
• Pet Store: 7% 
• Local animal rescue group: 2% 
• Other: 4% 
• Not Sure: 1% 


• Average number of litters a fertile cat can produce in one year: 3 

• Average number of kittens in a feline litter: 4–6 

• One female cat and her offspring can theoretically produce 420,000 cats in 7 years 

• Average number of litters a fertile dog can produce in one year: 2 

• Average number of puppies in a canine litter: 6–10 

• One female dog and her offspring can theoretically produce 67,000 dogs in 6 years

• Average cost of spaying or neutering a pet is less than the cost of raising a litter of puppies or kittens 

• On average it costs U.S. taxpayers approximately $100 to capture, house, feed, and eventually euthanize every homeless animal 

• Prevention is cheaper and more humane – the average cost to spay or neuter is only $40 per animal 

Pet owners can do their part by having their companion animals spayed or neutered. This is the single most important step you can take. 

Have your pet sterilized so that he or she does not contribute to the pet overpopulation problem, and adopt your next pet from an animal shelter rather than buying them from a breeder or pet store. 

Encourage your friends, family, and neighbors to do the same.

Figures, statistics, and surveys are from various sources, including, but not limited to: 

•PetSmart Charities
•Humane Society of the United States – Pet Overpopulation Facts (1999) 
•Save Our Strays
•Pet Savers Foundation
•Spay USA
• The USA Today, June 23, 1998, pg. 1
•National Council on Pet Population Study and Policy—Shelter Statistics Survey (1997 data) 
•The State of the American Pet—A Study Among Pet Owners. Prepared by Yankelovich Partners for Ralston Purina, October 2000.
Journal of Applied Animal Welfare Science, 1998, Volume 1, Number 3, p. 213