Research studies show that animals in low-income households are much less likely to be sterilized; by targeting low-income households, people who use the low-cost spay/neuter programs would otherwise have not been able to spay or neuter their pet. Low-cost spay and neuter programs lower the number of uncontrolled and accidental births each year. Targeted spay and neuter programs also lower the number of surrendered and stray animals brought into animal control and sheltering facilities.
Studies published in the Journal of the American Veterinary Medical Association about dogs and cats found that nearly one third of relinquishments could be directly attributed to the animals being sexually intact. A recent study conducted by Dorr Research Corporation found that in Massachusetts 87% of owned dogs are sterilized and 94% of owned cats are sterilized. Yet, a majority of the dogs and cats coming into adoption centers are intact animals. This means that while intact animals make up a minority of the population, they make up a large majority of the animals coming into animal control and sheltering facilities. Additionally, even though a majority of owned animals are sterilized, the same study also indicates that 12% of adult cats have had at least one litter of kittens (while the average is 2.4 litters with an average litter size of 4.2 kittens).