Animal-assisted therapy (AAT) is a type of therapy that involves animals as a form of treatment. The goal of AAT is to improve a patient's social, emotional, or cognitive functioning. Advocates state that animals can be useful for educational and motivational effectiveness for participants. In a variety of settings such as prisons, nursing homes, mental institutions, animals are used to assist people with different disabilities. A therapist who brings along a pet may be viewed as being less threatening, increasing the rapport between patient and therapist.[medical citation needed] The common used AAT includes canine-assisted therapy, equine-assisted therapy, and dolphin therapy. AAT is especially helpful in reducing the symptoms of psychological disorder, but most of the effects only last for a short period.
Wilson's (1984) biophilia hypothesis is based on the premise that our attachment to and interest in animals stems from the strong possibility that human survival was partly dependent on signals from animals in the environment indicating safety or threat. The biophilia hypothesis suggests that now, if we see animals at rest or in a peaceful state, this may signal to us safety, security and feelings of well-being which in turn may trigger a state where personal change and healing are possible. A contrast is sometimes made with Animal assisted activity (AAA). AAA is more casual and unstructured than AAT, involving perhaps more than one patient and with the primary focus on the presence of the animal itself. By contrast, AAT includes a handler which together with the animal has been trained for the role. AAT is more structured with specific objectives for each session. However, in common usage terms like these for animal assisted interventions are often used rather loosely.
Animals can be used in a variety of settings such as prisons, nursing homes, mental institutions, hospitals and in the home.[medical citation needed] Assistance dogs can assist people with many different disabilities; they are capable of assisting certain life activities and help the individuals navigate outside of the home.
As with all other interventions, assessing whether a program is effective as far as its outcomes are concerned is easier when the goals are clear and are able to be specified. The literature review identified a range of goals for animal assisted therapy programs relevant to children and young people. They include enhanced capacity to form positive relationships with others i-relief in pet ownership.
Therapists rely on techniques such as monitoring a child's behavior with the animal, their tone of voice, and indirect interviewing. These techniques are used, along with the child's pet or other animal, in order to gain information. Before pet therapy can be useful, the child and the animal must first develop a sense of comfort with each other, which is easier to achieve if the child's own pet is used. The applied technique that generates the most helpful information about the victim's experience is telling the child that the animal wants to know how they are feeling or what happened. AAT can be used in children with mental health problems, it can be used as a stand a lone treatment or it can be used along with conventional methods. Animals can be used as a distraction method when it comes to various situations, pain, and can also help bring in happiness, pleasure, and entertainments to the pediatric population. Animals can also help improve children's moods and reinforce positive behaviors while helping to decrease negative ones. Dogs in AAT can be an effective method to reduce pain in children as a complementary treatment.
Prison based animal-assistance programs involve an inmate working with a qualified handler to train an animal through a structured and goal-oriented program. The overall aim of using animal-assisted therapy in prisons is to relieve stress of the inmates and workers, enhance cognitive and behavioral capabilities, improve social skills, and to teach love, patience, and empathy in a realistic setting. Animal-assisted therapy is directly linked to increased physical and mental health benefits, induced relaxation, self-confidence, improved intrapersonal and interpersonal skills, and better environmental conditions. As of 2016 there are not many studies that examine animal-assistance programs at the prison level, especially in terms of long-terms effects, so the success rate cannot be accurately measured. However, effects from similar case studies such as rehabilitation programs or nursing homes can be evaluated and applied to the current state of the prison system in order to examine other alternatives to reform programs. If applied in prison settings results may show an increase in better environmental conditions and social support among staff and inmates by teaching them how to cope with hostile environments. It is likely the inmates will transfer the knowledge and skills learned in the correctional program to their transition outside of the institution, contributing to the larger society by generating productive members of society. Time in prison should be geared toward helping inmates build the life skills needed to push them down the right track, especially in the face of mental illness, loss, or addiction. The effect that animals have on a person's ability to understand love, empathy, and compassion are reasons to further explore animal-assisted therapy in correctional settings.
Animal assisted therapy draws on the bond between animals and humans in order to help improve and maintain an individual's function and is being used to assist in the process of enhancing the individual's quality of life in nursing homes.[non-primary source needed] Psychologists and therapists notice increasing unfavorable behaviors of elderly people that are transferred to nursing homes. Once the patients become settled into their new environment, they lose their sense of self-efficacy and independence. Simple, everyday tasks are taken away from them and the patients become lethargic, depressed, and anti-social if they do not have regular visitors.
When elderly people are transferred to nursing homes or LTC facilities, they often become passive, agitated, withdrawn, depressed, and inactive because of the lack of regular visitors or the loss of loved ones. Supporters of AAT say that animals can be helpful in motivating the patients to be active mentally and physically, keeping their minds sharp and bodies healthy. Therapists or visitors who bring animals into their sessions at the nursing home are often viewed as less threatening, which increases the relationship between the therapist/visitor and patient.
There are numerous techniques used in AAT, depending on the needs and condition of the patient. For elderly dementia patients, hands on interactions with the animal are the most important aspect. Animal assisted therapy provides these patients with opportunities to have close physical contact with the animals warm bodies, feeling heartbeats, caress soft skins and coats, notice breathing, and giving hugs. Animal assisted therapy counselors also plan activities for patients that need physical movement. These planned tasks include petting the animal, walking the animal, and grooming the animal. These experiences seem so common and simple, but elderly dementia patients do not typically have these interactions with people because their loved ones have passed or no one comes to visit them. Their mind needs to be stimulated in the ways it once was. Animals provide a sense of meaning and belonging to these patients and offer something to look forward to during their long days.
There are various animal species used in animal-assisted therapy (AAT). Individual animals are evaluated with strict criteria before being used in AAT. The criteria include appropriate size, age, aptitude, typical behaviors and the correct level of training. The most common forms of AAT are with dogs and horses. There is also published research on dolphin therapy.
Dogs are most common and popular companion animal. They are sensitive to the changes of human facial expression, behavior, and emotions, so un-surprisingly, dogs are good choice for animal assisted intervention with therapeutic aim. This intervention is called canine assisted therapy. Canine assisted therapy utilizes the interaction between clients and therapy dogs to enhance therapeutic activities and well-being such as physical, cognitive, behavioral and socio-emotional functioning of clients. Well trained therapy dogs exhibit the behavior that human clients construe as friendly and welcoming. They comfort clients via body contact. Therapy dogs are also required to possess a calm temperament for accommodating the contact with unfamiliar clients while they serve as a source of comfort. They promote patients engaging in interactions which can help patient improve motor skills and establish trusting relationship with others. The interaction between patients and therapy dogs also aids reducing stressful and anxious feelings patients have. Due to those benefits, canine assisted therapy is used as a complement to other therapies to treat diagnosis such as post-traumatic stress disorder (PTSD), attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and dementia. Except for using in the therapy, canine assistance can also be used in classroom for promoting the development of creative writing and living skills and the participation of children in group activities. There are programs called canine-assisted reading programs which facilitate children with special educational needs. These programs utilize the calm, non-judgmental, happy characteristics of canine to let the process of reading become more meaningful and enjoyable for children. With these benefits, researchers suggest to incorporating dogs into assisting learning and educational programs.
A distinction exists between hippotherapy and therapeutic horseback riding. The American Hippotherapy Association defines hippotherapy as a physical, occupational, and speech-language therapy treatment strategy that utilizes equine movement as part of an integrated intervention program to achieve functional outcomes, while the Professional Association of Therapeutic Horsemanship International (PATHI) defines therapeutic riding as a riding lesson specially adapted for people with special needs. According to Marty Becker, hippotherapy programs are active "in twenty-four countries and the horse's functions have expanded to therapeutic riding for people with physical, psychological, cognitive, social, and behavioral problems". Hippotherapy has also been approved by the American Speech and Hearing Association as a treatment method for individuals with speech disorders. In addition, equine assisted psychotherapy (EAP) uses horses for work with persons who have mental health issues. EAP often does not involve riding. Additional information pertaining to equine assisted therapy can be seen with Laira Gold's open clinical study of EAT.
Dolphin assisted therapy refers to the practice of swimming with dolphins. Proponents claim for such encounters "extraordinary results of the therapy and breakthroughs in outcomes",[non-primary source needed] however this form of therapy has been strongly criticised as having no long term benefit, and being based on flawed observations. Psychologists have cautioned that dolphin assisted therapy is not effective for any known condition and presents considerable risks to both human patients and the captive dolphins. Dolphin assisted therapy's agenda is to help people with autism, Down syndrome, and Cerebral Palsy with rehabilitation in motor function, speech, and language as well as to maintain and increase the client's attention span. The child has a one-on-one session with a therapist in a marine park of some kind. An ethical issue with data on dolphin-assisted therapy and the effectiveness of it is that most of the research is done by people who operate the dolphin-assisted therapy programs. Dolphin assisted therapy is an alternative medicine/therapy option for people who do not respond or are not keen on traditional medicines/therapies and it is a controversial therapy. John Lilly, who studied dolphin-human interaction, first considered this idea that interactions with dolphins can have rewarding benefits on humans in the 1960s. David Nathanson, who was a clinical psychologist, came up with much of the existing research on this therapy today. Nathanson's theory was that children with disabilities would increase their attention to related stimuli in the environment in hopes they would get to interact with the dolphins, helping motivate the child to do the task at hand and to give the appropriate responses according to that child's therapy program lessons.
Based on current research, there are many conditions/disorders that can benefit from animal-assisted therapy (AAT) in diverse settings around the world. Those conditions include psychological disorder, developmental disorder, dementia, cancer, chronic pain, advanced heart failure, etc. Animal-assisted therapy is commonly used for psychological disorder. Disorders such as attention deficit hyperactivity disorder(ADHD), autism spectrum disorder(ASD), post-traumatic stress disorder(PTSD), major depressive disorder (MDD) are part of psychological disorders that can benefit from animal-assisted therapy. 
In recent decades, an increase number of research indicates the social, psychological, and physiological benefits of animal assisted therapy in health and education field. The effectiveness of AAT in attention deficit hyperactivity disorder, post-traumatic stress disorder, autism spectrum disorder, and dementia has gradually been exposed to the public.
Children with attention deficit hyperactivity disorder (ADHD) may decrease behavioral issue and improve socialization skills with the intervention of AAT. Compared to children only received cognitive-behavioral therapy (CBT), children who received both canine-assisted therapy and cognitive-behavioral therapy (CBT) had reduce in severity of ADHD symptoms. However, the canine-assisted therapy had no effect on relieving ADHD symptoms in long-term treatment.
Canine assisted therapy is an encouraging and non-invasive method for treating post-traumatic stress disorder (PTSD) in veterans. In psychological condition, the interaction between canine and veterans supports social interactions for isolated veterans, reduces symptoms associated with PYSD such as depression and anxiety, and increases veterans’ calmness. In physiological condition, canine assistance can potentially mediate oxytocin which effects social and physical wellbeing and decrease blood pressure, and therefore can reduce the detrimental symptoms of PTSD in veterans. However, canine-assisted therapy also has the limitation. It may actually obstruct veterans from cultivating their own way of control over stressful situation. The effectiveness of AAT is still unclear due to the lack of scientifically based clarify regarding the degree to which the canine itself contributes in the recovery process.
AAT could reduce the symptoms of ASD such as aggressiveness, irritability, distractibility, and hyperactivity. Therapeutic horseback riding showed positive effects on children with ASD. It increased children’s ability of communication and decreased their ASD symptoms. The slow swing motion stimulates the vestibular system and therefore may help children with ASD produce speech sounds. Canine assisted intervention provided a calmer environment by reducing the stress, irritation, and anxiety that children with ASD were experiencing.  Playing with dogs increases the positive mood in children with ASD. Animals also can serve as a social catalyst. In the present of animals, children with ASD more likely engage in social interaction with human. However, the impact of AAT upon parent-child interaction is not clear.
The AAT program encourages expressions of emotions and cognitive stimulation through discussions and reminiscing of memories while the patient bonds with the animal. Many of the troubling symptoms in elderly dementia patients include decreased physical functioning, apathy, depression, loneliness, and disturbing behaviors. A study in 2017 evaluated results from ten research articles and found that animal assisted therapies (particularly using dogs) resulted in measurable quality of life improvements.
The limitation of pet therapy centers on the application during scenarios that involve adults who have been sexually assaulted. While pets do tend to cause more comfort to victims, pet therapy may not be the catalyst that provides positive success in therapy sessions. As mentioned above, adults tend not to focus as much on having an animal companion, and therefore, pet therapy cannot be attributed as the reason for success in those types of therapy sessions. Pet therapy does not raise any ethical concerns as far as advancing nonscientific agendas. On the other hand, there are some ethical concerns that arise when applying pet therapy to younger victims of sexual assault. For example, if a child is introduced to an animal that is not their pet, the application of pet therapy can cause some concerns. First of all, some children may not be comfortable with animals or may be frightened, so there would be ethical concerns with using pet therapy, which could be avoided by asking permission to use animals in therapy. Second, a special bond is created between animal and child during pet therapy. Therefore, if the animal in question does not belong to the child, there may be some negative side effects when the child discontinues therapy. The child will have become attached to the animal, which does raise some ethical issues as far as subjecting a child to the disappointment and possible relapse that can occur after therapy discontinues.The other limitation of animal assisted therapy is that AAT might be a short term reinforce, not a long term one. Also, for the dolphin-assisted therapy, it is harmful to the dolphins themselves; by taking dolphins out of their natural environment and putting them in captivity for therapy can be hazardous to their well-being.
Animal-assisted therapy sprouted from the idea and initial belief in the supernatural powers of animals and animal spirits. It first appeared in the groupings of early hunter gatherer societies. In modern times animals are seen as "agents of socialization" and as providers of "social support and relaxation". Though animal assisted therapy is believed to have begun in these early human periods it is undocumented and based on speculation. The earliest reported use of AAT for the mentally ill took place in the late 18th century at the York Retreat in England, led by William Tuke. Patients at this facility were allowed to wander the grounds which contained a population of small domestic animals. These were believed to be effective tools for socialization. In 1860, the Bethlem Hospital in England followed the same trend and added animals to the ward, greatly influencing the morale of the patients living there.
Sigmund Freud kept many dogs and often had his chow Jofi present during his pioneering sessions of psychoanalysis. He noticed that the presence of the dog was helpful because the patient would find that their speech would not shock or disturb the dog and this reassured them and so encouraged them to relax and confide. This was most effective when the patient was a child or adolescent. The theory behind AAT is what is known as Attachment theory.
Therapy involving animals was used in therapy by Dr. Boris Levinson who accidentally discovered the use of pet therapy with children when he left his dog alone with a difficult child, and upon returning, found the child talking to the dog. However, in other pieces of literature it states that it was founded as early as 1792 at the Quaker Society of Friends York Retreat in England. Velde, Cipriani & Fisher also state "Florence Nightingale appreciated the benefits of pets in the treatment of individuals with illness. The US military promoted the use of dogs as a therapeutic intervention with psychiatric patients in 1919 at St Elizabeth's Hospital in Washington, DC. Increased recognition of the value of human–pet bonding was noted by Dr. Boris Levinson in 1961".