2000 by Jean Donaldson

Audience: Executive Leadership, Foster Caregivers, Public, Shelter/Rescue Staff & Volunteers, Veterinary Team


As animal shelters achieve success at battling overpopulation, a new problem has come to light: dealing with dog behavior problems arising from long term shelter stays. Previously, dogs coming into shelters with behavior problems or dogs who developed behavior problems in shelters would have quickly been euthanized as competition for available kennel space went to the most highly adoptable dogs, of which there was no shortage. With population numbers coming under control and shelter stays lengthening, kennel space is now available for "behavior" dogs at many shelters.

Unfortunately, dogs with behavior problems tend to languish longer in shelters due to the understandable reluctance on the part of most adopters to take on a dog with possible ongoing behavior challenges. In addition, shelter staff often hold onto the dogs before making them available for adoption in order to work on the behavior problem. The resulting longer stay puts these dogs at increased risk of developing kennel-induced behavior problems as well as having an exacerbating effect on their existing problems.

The behavior problems seen in shelter dogs can be divided into four types.

1) Behavior problems correlated with relinquishment to animal shelters*:

  • House-soiling
  • Destructiveness
  • Noisiness
  • Fearfulness
  • Escaping

(*the same UCDavis study that made these findings, to be published this year, found dogs that had never had formal obedience training or were perceived by their owners to be unaffectionate or unattractive were also at elevated risk)

2) "adoption Buster" behavior problems. These are problems associated with dogs being passed over by potential adopters, once in a shelter:

  • Aggression towards people
  • Aggression towards dogs
  • Shyness
  • Kennel or barrier displaying
  • Jumpiness and mouthiness in initial meeting

3) Separation anxiety (not necessarily caused by shelter relinquishment - any time a dog changes owners, the risk of him developing separation anxiety goes up)


4) Problems caused by the kennel environment. These are:

  • Barrier-related barking
  • Barrier-related aggressionn style="line-height: 28px; letter-spacing: 0.03em;">Shyness
  • Housetraining regression
  • Social hyper-arousal

It is extremely important to note that the problems in categories three and four, those associated with the experience of being re-homed or being kenneled, are all found in categories one and two (or both). The inevitable conclusion is that the rehoming experience, especially through an animal shelter, can cause or exacerbate existing behavior problems, and the shelter experience itself then negatively impacts the dogs adoptability and increases the likelihood of future relinquishment.

Clearly, to be successful at placing longer term dogs, shelters must address the issues of separation anxiety, kennel presentation (barrier issues and social hyper-arousal) and housetraining to improve their track records at placing behavior-case dogs. What follows are overviews of shelter-stay related problems and possible strategies to mitigate kenneling effects and/or solve behavior problems in our shelter dogs.

Separation Anxiety

The prevailing theory of separation anxiety - with its characteristic distress vocalizing, panic elimination and property destruction - stresses that dogs who do not learn to cope with separation from their owners or have developed an overly intense attachment due to continuous access are at increased risk of its development. Furthermore, if dogs are abandoned or lose their owners, they may develop overly intense and insecure attachments to subsequent owners (Borchelt & Voith, 1982 & 1985, McCrave 1991). This is the rehoming dilemma.

Separation anxiety is frequently kicked off by a long period of constant togetherness followed by an abrupt, enforced separation. A typical scenario is a dog acquired by someone during a work hiatus. The dog is with the owner twenty four hours a day, seven days a week and, when the hiatus ends, is suddenly confronted with daily 8 - 10 hour absences. Separation anxiety ensues. Another common presentation would be the development of separation anxiety following boarding or rehoming. It has also been suggested that artificial selection for more affectionate, neotenized animals has increased the genetic tendency towards separation anxiety in domestic dogs (Fox, 1978, Serpell, 1983, Mugford, 1985).

Shelters can both minimize the incidence of separation anxiety and resolve many cases by implementing the following:

  1. Environmental enrichment to alleviate general distress during the dog's shelter stay. These efforts can include: walks, clicker and/or obedience training, group or pairs housing and/or regular dog-dog free play, food delivery enrichment strategies and training efforts directed at the dog's particular behavior problem(s). Most of these are time-intensive and require adequate training in execution for staff or volunteers administering them.
  2. Effective intervention when separation anxiety develops. This requires good knowledge of systematic desensitization and pharmacological intervention on the part of shelter staff and veterinarians and management/support options for owners during the course of treatment.
  3. adoption counseling. Thoroughly briefing adopters on do's and don't's about the early weeks and months with their newly adopted dog, as well as supplying ongoing support to adopters in order to diagnose and address separation anxiety early on. For instance, it is imperative to avoid smothering new dogs with attention their first few days home. It is understandable that owners are fascinated by their new pets and want to make the new addition feel welcome and happy, however constant togetherness sets the dog up for a fall when normal life is finally resumed. It is far better to avoid high contrasts in home and away time, the rule of thumb being many absences, beginning with extremely brief (>1 minute) ones and gradually progressing to longer over the first few days.
  4. Dog behavior education. Aggressive community outreach to dog owners and the general public who may one day be dog owners, with good, catchy information on management, behavior and training (including home-alone training) - to prevent relinquishment for behavior reasons from ever happening in the first place.

Barrier-related Barking and Aggression

Dogs get important information about other beings with their noses and through up-close interaction and investigation. Most dogs therefore feel compelled to make social contact when they see a person or dog. In a kennel, tie-out or in many on-leash situations, they may be repeatedly unable to do so. The result is barrier-frustration. Barrier frustration behaviors - barking, lunging and aggressively displaying at dogs or people from behind bars, fence or glass - exemplify the general concept of "thwarting": the physical prevention of an animal behaving as it is highly motivated to behave.

Physiological stress responses, emotional states and certain well-known behaviors (agitation, barking, aggression) can all be reliably predicted by thwarting scenarios, especially chronic ones. The epidemic of thwarting situations in the daily lives of dogs is not yet widely recognized, nor the impact it has on their behavior. Most notably, environmental exploration and establishment of social contact with people and other dogs are prohibited by leashes, fences and enforced obedience.

It would be difficult to design a more frustrating environment for a dog than a kennel. In most kennels, dogs are kept alone in extremely barren environments virtually around the clock, with some tantalizing visual access to the outside world. This low-stimulation situation is then punctuated by people and other dogs going by - they're always visible but they can't be investigated. The dog's urge to meet and investigate is repeatedly frustrated. With repetition, the sight of dogs and/or people becomes associated, through classical conditioning, to the feelings of frustration and agitation. When the dog finally has the opportunity to meet, his behavior is over the top in intensity and may be aggressive.

The dog's poor social behavior may then cause the staff to prohibit the dog from further social contact. In addition, defensive responses from the other dogs he encounters or punishment by walkers for unruly or seemingly aggressive behavior may make the dog's behavior even worse. The sight of dogs and/or people may then be associated with a high likelihood of punishment and aggressive responses from other dogs, along with the original frustration. This results in further deterioration of behavior and a cycle develops.

Barrier frustration usually manifests in a shelter environment as dramatic barking and lunging displays at passers-by to the dog's kennel. This can bleed over to on-leash lunging and aggression and, with sufficient time for classical conditioning to take place, aggression directed at people or dogs, including out of the original context of the kennel or other thwarting situation.

This is a severe problem. Fortunately, however, it's well-understood and relatively simple to remedy by:

  1. Preventing visual access to corridor to dogs prone to in-kennel display or, possibly, to all dogs in kennel (this needs research), or
  2. Counterconditioning a competing emotional response as people walk past the dog's kennel. The easiest practice is to use part of the dog's daily meal ration. The dog's food is stored conveniently near his kennel - any person grabs a few pieces before passing by and delivers them to the dog on his/her way by. The food elicits eating behavior, which prevents lunging, barking and aggression. This simple technique can also be used to ameliorate an existing barrier-frustration problem in many cases.

This latter solution is more labor-intensive and requires kennel design to incorporate regular food delivery in this manner. However it has nice fringe benefits (socialization, conditioned emotional response to people/dogs and the possibility of using food to reward desired behavior such as sitting) whereas the management by blocking visual access approach requires some rudimentary kennel remodeling.

Housetraining Regression

Dogs adopted out from animal shelters will often lapse in their housetraining following their stay in the shelter. The likely reasons are:

  1. Kenneling forces elimination in the dog's living quarters. The habit of deferring elimination is therefore temporarily monkey-wrenched (note: previously housetrained dogs re-learn to defer elimination quickly if properly managed the first few weeks in their new homes).
  2. Newly adopted dogs are sometimes given too much freedom initially by well-meaning owners, sometimes to the point of allowing inappropriate elimination habits to become ingrained in the new setting.
  3. Dogs are poor generalizers to start with. When dogs learn where to eliminate they are not learning an indoor vs. outdoor concept but something much more specific, such as "never eliminate in these rooms" (the rooms in the particular house the dog lives in). Therefore, rehoming in and of itself can cause innocent housetraining accidents - the dog is unsure whether the same rules apply in the new home. Humans, being master generalizers, do not easily empathize with dogs and fail to take cautionary measures.

A few different measures might address this concern:

  1. In-shelter crate training. David Tuber (who audio-taped hundreds of dogs home alone) found that if shelter dogs were gradually acclimated, over several days at the shelter, to staying in a large, airline crate and then sent home with that crate and instructions on its proper use, the likelihood of the person keeping the dog was greatly increased. It is likely that both housetraining and chew-training mishaps were thus minimized.

    Crates can become associated with comfort and safety during a dog's stay in a noisy, drafty kennel. The crate contrasts positively with the ambient environment. The opposite often occurs when owners try to crate-train dogs in their homes. The crate negatively contrasts with the pleasant house the dog is living in. It is therefore wise to establish crates while dogs are in animal shelters, both to relieve stress and to achieve an early positive association with the crate through the positive contrast effect.
  2. Prioritizing housetraining at animal shelters. This is, again, a staff and/or volunteer intensive undertaking. Dogs would need to be walked at least three to four times per day and possibly crated if they were not holding their bladders in their kennels. Kennel runs could also be made more home-like with the use of tile or linoleum substrate and inclusion of rudimentary furniture items. An alternative would be foster-care for dogs suspected of not being
    housetrained. Certain foster homes might specialize in adult house-training.
  3. Post-adoption support. This could be in the form of scheduled counseling appointments or, in lower risk cases, phone follow-up. Not only should adopters leave with solid information on what to expect and how to train their new dog, they must know there is a safety net should they feel overwhelmed.

Social Hyper-arousal

Everyone pays lip service to the refrain that dogs are social animals and yet most animal shelters in the US are still housing dogs singly, for days, weeks and sometimes months at a time. The result, at worst, is compulsive behaviors in the form of pacing, circling, bouncing off walls and self-directed behavior and, at best, over-excitement on those occasions when the dog gets social contact. This is off-putting to potential adopters who are likely to label a dog "hyperactive" or unmanageable rather than see the dog's behavior as driven partly by the abnormal context. The solution is, again, multi-fold:

  1. Group housing, pairs housing and regular dog play groups. It is hard to overestimate the value of free dog interaction, both from the standpoint of development of social skills (with resulting lowered risk of dog-dog fear or aggression problems) and environmental complexity. Logistical problems are not insurmountable and the likely higher frequency of agonistic behavior (i.e. fights) is far outweighed by the benefits to most individual animals.
  2. Time spent with shelter dogs that is just an in-kennel visit (i.e. simple, low-key hanging out with dog) rather than "action" oriented. If all visits to dogs' kennels predict walks, exiting the kennel or feeding time, humans become classically conditioned predictors of excitement. This can obviously worsen existing hyper-arousal when potential adopters meet kenneled dogs. Kennel runs could be provided with seating to make them more human-friendly. Books or magazines could be on-hand to promote inactive human presence.
  3. Regular training. This teaches the dog specifically how to behave in a visit-to-kennel situation as well as providing much-needed problem solving (training, if reward-oriented is extremely enjoyable to most dogs). Even when dogs master basic obedience, there is no limit to what they can be taught with techniques like clicker training, which further enhances their adoptability and degree of mental stimulation. Clicker training is easy to learn, forgiving of trainer error (and so can be implemented by moderately skilled volunteers) and has the added fringe benefit of giving the dog a sense of partial control over his stress-filled environment.


Both environmental stimulation and rehabilitation of shelter dogs with serious behavior problems are fields in their infancy. The next few years are likely to yield important insights and technical breakthroughs, which will have significant impact on the quality of life of dogs in shelters and number of dogs saved.

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Jean Donaldson

Jean Donaldson is a widely known and respected dog behaviorist and trainer. Her two books, The Culture Clash and Dogs Are From Neptune have exploded many of the myths we hold about our "best friends". Her aim is to provide accurate and "user friendly" information to enable dog lovers to build harmonious relationships with their canine companions.Jean is currently on staff at The San Francisco SPCA where she is formulating a new dog training model for both sheltered and owned animals. Previously, she ran her own dog training school in Montreal, Canada.