Center for Animal Welfare Legal Protection    
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Autonomous non-profit organization
Center for Animal Welfare Legal Protection

The role of animal shelters in controlling pet overpopulation

Carol Moulton, MA; Phyllis Wright; Kathryn Rindy
The Journal of the American Veterinary Medical Association (JAVMA), Vol. 198, No. 7, April, 1991

      Pet overpopulation ("pet" being used in this context to mean dogs and cats) surfaced as a specific problem in the 1940s. American Humane Association newsletters prior to 1940 had hundreds of articles about the abuse of horses and dozens on cruelty to dogs or cats, trapping, rabbit coursing, hunting, and farm animal suffering, but few on overpopulation as a specific problem. It can be conjectured that urbanization combined with advances in veterinary medicine created conditions for the problem to developurbanization because it concentrated greater numbers of pets in smaller areas, which facilitated random breeding, and veterinary medicine because healthier animals living longer lives would also have increased ability and opportunity to reproduce.
       Through the 1940s to the present time, the animal sheltering system grew alongside the overpopulation problem. Inasmuch as shelters traditionally represent the front-line response to the problem of pet overpopulation, it seems appropriate to describe the 3 basic types of operations.

Types of Shelters
      Public shelters (animal control agencies) Tax funds and user fees support public shelters and animal control programs. Animal control holding facilities are sometimes referred to as pounds, short for "impoundment facilities." The functions of an animal control agency are to enforce animal control ordinances, pick up and receive surplus and stray animals, and protect the health and welfare of people in the community by minimizing occurrences of animals damaging property, threatening human beings, causing automobile accidents, disturbing the peace, and spreading disease. Animal control agencies of municipalities now realize that preventing these problems may be more economical than attempting to correct them after they have developed. Thus, there is more interest in public education efforts.
      Private shelters (humane agencies) Most areas, urban and rural, are served by one or more private humane agencies (called the Humane Society, Animal Rescue League, the Society for the Prevention of Cruelty to Animals, or other names implying animal welfare activities) that are usually nonprofit, tax-exempt, charitable agencies dependent on bequests and donations to fund their operations. Private agencies that accept all animals brought to them must euthanatize animals not claimed or adopted within a certain period. Euthanasia occurs frequently, because the number of incoming animals is great and space and funds are limited. Agencies that do not euthanatize animals (no-kill shelters) do not have the space to admit all pets brought to them, and typically turn away many animals. No-kill shelters usually have long waiting lists of pet owners wishing to surrender animals, and many of those owners must find other alternatives.
      Private humane agencies frequently have educational programs on animal care and welfare. Potential adopters of shelter animals are counseled and educated on pet care and ownership responsibilities before being allowed to adopt. Additionally, new owners generally are required to spay or neuter the adopted animal. Private agencies have various follow-up procedures to ensure compliance with the spay/neuter rule, or they may have their own spay/neuter surgery facility to accomplish this. Private agencies also may provide programs such as animal rescue services, obedience training for dogs, advice on behavioral problems, and cruelty investigations.
      Private agency with public contract The third type of shelter is run by a private, nonprofit agency that has negotiated a contract with a city or county government to perform animal control and enforcement activities for the community. Sometimes the shelter only houses impounded animals, whereas animal control officers are dispatched and supervised by the police department. In other cases, a private agency may hire, train, and supervise animal control officers, as well as house impounded animals. Private agencies collect fees from local governments for animal control service, but may seek private donations to support other programs, such as humane education and animal rescue.

      In the late 1940s, private, nonprofit organizations became concerned that city and county governments were not providing adequate care to impounded animals. Private shelters were established to receive lost and unwanted animals. As the number of surrendered and abandoned animals grew, many private humane societies began to provide contracted animal control and sheltering services.
      In the 1950s, public animal shelters were working primarily to address the growing problem of rabies in wild and domestic animals. Many cities simply rounded up dogs and shot them to prevent surplus animals from spreading rabies [1]. As better vaccination and licensing programs were implemented, statistics from the Centers for Disease Control reflected the trend that followed: 7,344 domestic animal cases of rabies in 1953, and 516 in 1986 [2].
      Also in the 1950s, hundreds of local humane societies initiated varying approaches to educating pet owners on the pet overpopulation problem. Programs conducted at schools and animal shelters, along with announcements on pet overpopulation distributed through the news media, informed the public about the surplus of dogs and cats. Identifying and describing pet overpopulation was an important first step, but programs designed to prevent the problem did not surface until the 1960s. Generally, programs for preventing pet overpopulation emphasized neutering of dogs and cats.
      The role of legislation and enforcement in combating pet overpopulation has been explored during the past 2 decades.
      The decades of the 70s and 80s saw the establishment of many low-cost spay/neuter clinics associated with private and public agencies, and mandatory spay/neuter requirements for animals adopted from most shelters. The concept of restricting adoptions to qualified applicants rather than giving animals to anyone became widespread and led to the adoption screening now practiced in most private and in many public shelters.

Table 1. National estimates (in millions) of shelter entry and exit* (1985-1988).

in millions (%)
in millions (%)

8.2 - 13.6 (48.40)
8.7 - 14.5 (51.60)
16.9 - 28.1 (100.00)

6.1 - 10.2 (57.30)
4.6 - 7.6 (42.70)
10.7 - 17.8 (100.00)

3.0 - 5,0 (20.16)
1.9 - 3.2 (12.90)
9.9 - 16.6 (66.94)
14.8 - 24.8 (100.00)

1.8 - 3.0 (18.52)
0.2 - 0.3 (1.85)
7.8 - 12.9 (79.63)
9.8 - 16.2 (100.00)

6.4 - 10.6 (40.60)
9.1 - 15.2 (59.40)
15.5 - 26.1 (100.00)

5.7 - 9.5 (49,00)
6.0 - 9.9 (51.00)
11.7 - 19.4 (100.00)

2.9 - 4.8 (21.00)
2.6 - 4.4(19.00)
8.3 - 13.8 (60,00)
13.8 - 23.0 (100.00)

2.3 - 3.8 (19.00)
0.3 - 0.6 (3.30)
9.3 - 15.4 (77.70)
11.9 - 19.9 (100.00)

4.9 - 8.3 (44.70)
6.3 - 10.5 (55.30)
11.2 - 18.8 (100.00)

4.5 - 7.4 (50,00)
4.4 - 7.3 (50.00)
8.9 - 14.7 (100.00)

2.4 - 4.0 (23.00)
1.5 - 2.6 (15.00)
6.3 - 10.4 (62.00)
10.2 - 17.0(100.00)

1.6 - 2.6 (21.00)
0.2 - 0.3 (2.00)
5.9 - 9.9 (77.00)
7.7 - 12.8 (100.00)

4.2 - 7.1 (40.80)
6.1 - 10.1 (59.20)
10.3 - 17.2(100.00)

2.7 - 4.5 (45.80)
3.2 - 5.3 (54.20)
5.9 - 9.8 (100,00)

1.7 - 2.9 (19.30)
1.3 - 2.2 (14.80)
5.8 - 9.6 (65.90)
8.8 - 14.7 (100.00)

1.0 - 1.7 (18,90)
0.1 - 0.2 (2.20)
4.3 - 7.1 (78.93)
5.4 - 9.0 (100.00)
     *The range of estimates is attributable to the lock of information concerning tlia number of animal shelters operating in the country. A more conservative estimate of 3,000 shelters is used for the lower values (first column), and an estimate of 5,000 shelters was applied for the higher values (second column). tMost of the difference in the totals for entry and exit is attributable to animals entering the shelter during the month and still on hand at the end of the month.
     From The American Humane Association's Animal Shelter Reporting Study, 1985-1988.

     In 1976, the AVMA, the Humane Society of the United States, the American Humane Association, and the Pet Food Institute developed a Mode! Dog and Cat Control Ordinance, which included basic provisions that have been adopted by communities all over the United States.
     National statistics, kept since 1985, on animals entering and exiting shelters (Table 1) show little decrease in numbers of animals euthanatized, but pet overpopulation undoubtedly would be worse without the efforts of the past 3 decades.
     Nevertheless, some agencies have reported substantial decreases in the number of animals euthanatized. Other agencies, though they have not decreased intake numbers, have raised adoption and reclaim rates, which has resulted in fewer animals being euthanatized. These agencies commonly engage in one or more of a number of techniques.

Current Practices
I. Aggressive action to promote or require spaying and neutering of animals.
     Animals that are neutered cannot add to the problem of overpopulation. People who adopt intact animals from a shelter can be held to a contract requiring them to have the newly acquired pet neutered. Those who have obtained animals from other sources must be educated, coaxed, and often financially subsidized before acquired pets are neutered. An ongoing publicity campaign about overpopulation, availability of low-cost surgery, and differential license fees that favor neutered dogs and cats are approaches that encourage neutering.
     In January 1982, the city of Charlotte, NC, opened a municipal spay/neuter clinic, administered by the Humane Society of Charlotte. From January 1982 to July 1989, the clinic neutered 27,773 dogs and cats. Clinic activity was fueled by a high differential for license fees ($20 for unneu-tered dogs and cats, $5 for neutered animals), and by a requirement that animals adopted from the shelter be neutered. The number of stray dogs processed through the Charlotte/Mecklenburg Animal Control Center decreased 61.6% between 1980 and 1989. Cats were not required to be licensed until 1982, the year the spay/neuter clinic opened and the city and county shelters merged. That was the firstyear records were kept on cats and the first year Charlotte enforced licensing requirements. Each year after 1982, the number of cats in each category (stray, owner-released, euthanatized, and total handled) increased because enforcement was intensive. Fiscal 1988/89 showed the smallest increase yet, and a decrease was expected in 1989/ 90 (ref: Wright P. "Complaints from citizens to Humane Society of the United States, 1950-60".).
     The Humane Society of Huron Valley opened a spay/neuter clinic in March 1975, and performed 31,155 surgeries in the next 10 years.The society reported a decrease in dogs and cats handled by the shelter: from 16,500 in 1975 to 8,744 in 1984 [3]
     Perhaps the most successful cooperative effort between animal shelters, veterinarians, and health departments operates in New Jersey. A state law mandates that anyone adopting a dog or a cat from a licensed, nonprofit animal shelter, a municipal, county, or regional pound, or a New Jersey holding or impoundment facility that contracts with New Jersey municipalities may have the animal neutered for a fee of $20. Economically disadvan-taged pet owners may have their pets neutered for $10. New Jersey law requires all dogs to be inoculated for rabies and licensed before sterilization. The New Jersey Health Department strongly encourages the inoculation of cats as well.
     Funding for the New Jersey program comes from a $3 surcharge on dog licenses, paid by the owners whose pets are unaltered, and by the $10 and $20 fees. There is no expense to the state or any municipality. Participating veterinarians throughout the state perform the surgery for 80% of their regular fee and are paid out of the fund.
     The 1987 New Jersey law was supported by the New Jersey Veterinary Medical Association, which, in May of 1986, passed a resolution endorsing spay clinics and programs. Although they still oppose full-service clinics operated by nonprofit organizations, the cooperative efforts are working in this state; since the program's inception in 1983, a total of 24,954 pets have been neutered (ref: Lewis PG, President, Humane Society of Charlotte, NC: Personal communication, 1990.).

II. Passing tough laws with strict enforcement
     Laws that force change in human behavior may be required to control the pet overpopulation problem. The Atlanta Humane Society, which also performs animal control for Fulton County, Ga, handled over 50,000 animals in 1974. At that time, animal control ordinances were weak, enforcement was poor, and "significant" fines were not imposed on offenders. By strengthening and standardizing ordinances, and by a deliberate effort to educate judges and prosecutors about community problems attributable to pet overpopulation, Atlanta now has specific days and courts for animal cases. First offenders for "dog-at-large" routinely receive fines of $200, suspended on proof of fence or run construction. With increased penalties, the Atlanta Humane Society experienced a brief increase in the number of dogs handled, as people relinquished animals rather than pay a fine or construct an area for confinement. By 1983, however, the number of dogs and cats coming into their facilities was down to 25,500almost half the number handled a decade earlier [4].
     Strong enforcement of licensing laws requiring tagging and a substantial differential in licensing fees favoring neutered animals are other forces for controlling overpopulation. Not only do such licensing laws encourage neutering, they increase the number of lost and stray animals that can be returned to their homes, because the license is traceable and the "owners" can be notified when their animals are found.

III. Improving lost-and-found programs
     Almost half of the animals coming into shelters are strays. If not found, reclaimed, or adopted, these animals increase the number of euthanatized petsand pet overpopulationjust as surely as do newborn pups and kittens that are not adopted.
     Some owners do not try to search for a lost pet, but even for those who do, there are many reasons why lost or stray animals may not be found and reclaimed. Legal stray holding periods range from 72 hours to 5 days, which probably is an excessively short time for a thorough search, when one con siders that many cities have more than one shelter (Denver, for example, has 13, each harboring from 100 to 400 pets per day) and a lost animal could end up in any one of them.
     Standardizing descriptions of lost animals is another problem. Some owners (and, unfortunately, shelter workers) cannot tell the sex of an animal, and the same coat color might be variously described as beige, champagne, apricot, or brown. To cope with these and other problems of searching for lost pets, shelters are turning to computers. Inasmuch as the computer can do a quick search on a number of characteristics, the possibility of an over-the-phone search being successful are greatly improved. In the first 2 years that the Denver Dumb Friends League operated its own in-house computer, it experienced a 28.7% increase in the number of reclaimed animals. Even more promising was the number of unsheltered lost animals (those found by people who phoned in a description but did not bring the animal to the shelter) reunited with their owners (who phoned in descriptions of their missing animals) through the League's ability to computer-match the phoned-in reports. The figure increased over 100% in the first year of the computer's use, and continues to increase substantially (ref: Monyer R, Coordinator, Health Projects III, Animal Population Control, Biological Services Program, Department of Health, State of New Jersey: Personal communication with N. Austenburg, 1990.). In some cities, computer networks have been formed to link the records of all animal shelters in the area onto one data base. PetNet in Dallas, which is a lost-and-found system, and the MASC system in Denver, which provides 10 public and private shelters access to license tag data in a 3-county area, are 2 examples.
     The best way for owners to ensure the return of lost animals is to keep them tagged, with phone numbers and addresses included on the tags. Strong licensing enforcement programs make a difference by forcing negligent owners to tag their pets. Such programs may include canvassing neighborhoods to identify homes where pets are kept, with a follow-up visit at addresses where no current pet license is on record, increasing the availability of license application forms by mail distribution, special low-cost or free rabies vaccination clinics where the license tag is included or required, "significant" fines for harboring an unlicensed pet, and publicity on the legal requirement that pets wear a license tag.

Increasing the number of animals adopted
     According to a recent survey of 391 Dog Fancy readers, 46% obtained their dogs from breeders, 13% from shelters, 9% from pet stores, 10% from newspaper ads, 10% from neighbors, 10% as strays, and 2% from breed rescue clubs [5]. A similar survey in Cat Fancy showed that 36% of the cats owned were strays, 21% were from shelters, 30% were from neighbors, and 13% were purchased from pet stores (ref: Rohde B, Director, Denver Dumb Friends League: Personal communication, 1990). Although these percentages would vary somewhat depending on what group is surveyed, it probably would remain true that a small percentage of owned animals would be obtained from animal shelters. The benefit of increasing the number of animals adopted from shelters is that the new owners will receive counseling on pet care issues, including overpopulation, and those pets will be more likely than pets from other sources to have been neutered. The object is not to create more homes for pets by persuading people who would not otherwise have gotten a pet to get one, but to persuade people who would otherwise get a pet from some other source to get that pet from the shelter instead. To increase their "market share," shelters have become more aggressive about promoting the fact that they have healthy animals available for adoption through public service announcements, advertising, and national promotions such as Adopt-A-Cat Month and Adopt-A-Dog Month.

Reaching the public
     There will always be sources other than animal shelters for obtaining pets. Thus, perhaps the most challenging aspect of addressing pet overpopulation lies in reaching and effecting change in those people who have no contact with animal shelters. Because shelters are the primary source of information about pet overpopulation, they serve as the public's primary association with this issue. Except for those animals that have been temporarily separated from their owners, shelters handle only unwanted and surplus animals, most of which will be euthanatized because there is no market for them.
     For many people, their concern with pet overpopulation may have as its primary focus the rates of euthanasia associated with various shelters. Pet overpopulation is then seen as the individual shelter's problem, if not fault, when, in reality, the shelter is dealing with the whole community's disposal of its pets. Changing this perception involves convincing pet owners of their participation in the cause of the problem and of the importance of their participation in the solutions to the problem. One of the most difficult aspects of this is that "pet overpopulation" may seem abstract to the pet owner who might "have just one litter." One an-irnal, or even a handful of animals from one person, does not seem like an insurmountable problem. When that person can perceive a human population already saturated with pets and 10 or 20 people bringing litters into each animal shelter daily, the picture becomes more clear.
     Pet overpopulation comes from many sources: from people who breed animals intentionally for profit or hobby; from people who unintentionally allow their pets to breed, for any reason; from animals abandoned and left to fend for themselves, reproducing litters; from animal shelters that do not ensure that the pets they offer for adoption are spayed or neutered; from pet owners who allowtheir unneutered pets outside, where they do breed. Pet overpopulation is not the millions of surplus animals born each year, but one animal or one litter turned in, given away, sold, abandoned, or no longer cared for. This correlation is rarely understood by individuals turning in, giving away, selling, or abandoning their animals.
     The challenge for animal shelters and others concerned about this issue is to reach people before they reach the point of giving up their pet, before they allow their pets to breed, and, in many cases, before they make the decision to get a pet in the first place. This effort is being made not only by animal shelters, but by concerned individuals many of whom are veterinarianswho are com mitted to educating people about the realities of pet overpopulation. This is not a' 'shelter problem" but a community problem. Working together, we can and are making a difference.

1. Rabies surveillance 1986. MMWR 1987;36(35):175.
2. How to establish spay/neuter programs and clinics.
Bethesda, Md: The Humane Society of the United States, 1987;6
3. Garrett W. Animal control in Fulton County, in Proceedings. Workshop Anim Control 1985;49-50.
4. Wibbens W. From dumpsters to breeders. . . . Dog Fancy 1990;33(6):66-73.
5. Rach j. How cats find homes. Cat Fancy 1989; 3(1):28-32.

            Authers of article are from the American Humane Association, Animal Protection Division, 63 Inverness Dr East, Englewood, CO 80112. (Moulton) and the Humane Society of the United States, 2100 1- St NVV, Washington DC, 20037. (Wright, Rindy)

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